1. consider the lewis two sector model. what are the 2 main assump

1. Consider the Lewis two-sector model. What are the 2 main
assumptions related to the traditional sectors? How these
assumptions help explaining the constant flow of workers from
the traditional to the modern sector?
2. Consider the Child Labor Multiple Equilibria Model. How is
it possible to have 2 equilibria? What the government can
possibly do to deal with it? Explain your answers.
Original Investigation | Psychiatry
Assessment of Relationship of Ketamine Dose With Magnetic
Resonance
Spectroscopy of Glx and GABA Responses in Adults With
Major Depression
A Randomized Clinical Trial
Matthew S. Milak, MD; Rain Rashid, BS; Zhengchao Dong,
PhD; Lawrence S. Kegeles, MD, PhD; Michael F. Grunebaum,
MD; R. Todd Ogden, PhD; Xuejing Lin, MA;
Stephanie T. Mulhern, BA; Raymond F. Suckow, PhD; Thomas
B. Cooper, MA; John G. Keilp, PhD; Xiangling Mao, MS;
Dikoma C. Shungu, PhD; J. John Mann, MD
Abstract
IMPORTANCE A single subanesthetic dose of ketamine
produces an antidepressant response in
patients with major depressive disorder (MDD) within hours,
but the mechanism of antidepressant
effect is uncertain.
OBJECTIVE To evaluate whether ketamine dose and brain
glutamate and glutamine (Glx) and

γ-aminobutyric acid (GABA) level responses to ketamine are
related to antidepressant benefit and
adverse effects.
DESIGN, SETTING, AND PARTICIPANTS This randomized,
parallel-group, triple-masked clinical trial
included 38 physically healthy, psychotropic medication–free
adult outpatients who were in a major
depressive episode of MDD but not actively suicidal. The trial
was conducted at Columbia University
Medical Center. Data were collected from February 2012 to
May 2015. Data analysis was conducted
from January to March 2020.
INTERVENTION Participants received 1 dose of placebo or
ketamine (0.1, 0.2, 0.3, 0.4, or 0.5
mg/kg) intravenously during 40 minutes of a proton magnetic
resonance spectroscopy scan that
measured ventro-medial prefrontal cortex Glx and GABA levels
in 13-minute data frames.
MAIN OUTCOMES AND MEASURES Clinical improvement
was measured using a 22-item version of
the Hamilton Depression Rating Scale (HDRS-22) 24 hours
after ketamine was administered.
Ketamine and metabolite blood levels were measured after the
scan.
RESULTS A total of 38 individuals participated in the study,
with a mean (SD) age of 38.6 (11.2) years,
23 (60.5%) women, and 25 (65.8%) White patients.
Improvement in HDRS-22 score at 24 hours
correlated positively with ketamine dose (t36 = 2.81; P = .008;
slope estimate, 19.80 [95% CI, 5.49
to 34.11]) and blood level (t36 = 2.25; P = .03; slope estimate,
0.070 [95% CI, 0.007 to 0.133]). The

lower the Glx response, the better the antidepressant response
(t33 = −2.400; P = .02; slope
estimate, −9.85 [95% CI, −18.2 to −1.50]). Although GABA
levels correlated with Glx (t33 = 8.117;
P < .001; slope estimate, 0.510 [95% CI, 0.382 to 0.638]),
GABA response did not correlate with
antidepressant effect. When both ketamine dose and Glx
response were included in a mediation
analysis model, ketamine dose was no longer associated with
antidepressant effect, indicating that
Glx response mediated the relationship. Adverse effects were
related to blood levels in men only
(t5 = 2.606; P = .048; estimated slope, 0.093 [95% CI, 0.001 to
0.186]), but Glx and GABA response
were not related to adverse effects.
(continued)
Key Points
Question What is the relationship
between the antidepressant effect of
ketamine and ketamine dose and blood
level, and is its antidepressant effect
mediated by an effect on ventro-medial
prefrontal cortical glutamate and
glutamine or γ-aminobutyric acid
response?
Findings This randomized clinical trial
of 38 patients with major depression

found a relationship of ketamine dose
and blood level with antidepressant
response at 24 hours. Ketamine
suppression of glutamate and glutamine
in the ventro-medial prefrontal cortex
mediated the relationship of ketamine
dose and level with antidepressant
effect but was unrelated to
psychotomimetic side effects.
Meaning The findings of this study
suggest that glutamate and glutamine
suppression by ketamine may be a
potential biomarker of rapid
antidepressant effect and that a fast-
acting antidepressant without
psychotomimetic adverse effects may
be possible.
+ Visual Abstract
+ Supplemental content

Author affiliations and article information are
listed at the end of this article.
Open Access. This is an open access article distributed under
the terms of the CC-BY License.
JAMA Network Open. 2020;3(8):e2013211.
doi:10.1001/jamanetworkopen.2020.13211 (Reprinted) August
12, 2020 1/14
Downloaded From: https://jamanetwork.com/ by Agata Boxe on
01/21/2021
https://jama.jamanetwork.com/article.aspx?doi=10.1001/jamanet
workopen.2020.13211&utm_campaign=articlePDF%26utm_med
ium=articlePDFlink%26utm_source=articlePDF%26utm_content
=jamanetworkopen.2020.13211
Abstract (continued)
CONCLUSIONS AND RELEVANCE In this study, intravenous
ketamine dose and blood levels
correlated positively with antidepressant response. The Glx
response correlated inversely with
ketamine dose and with antidepressant effect. Future studies are
needed to determine whether the
relationship between Glx level and antidepressant effect is due
to glutamate or glutamine.
TRIAL REGISTRATION ClinicalTrials.gov Identifier:
NCT01558063

doi:10.1001/jamanetworkopen.2020.13211
Introduction
Major depressive disorder (MDD), a leading cause of disability
worldwide,1 affects more than 16
million adults in the United States,2 with estimated costs of
$210.5 billion in 2010, a 21.5% increase
from 2005.3 Response to currently marketed antidepressants
generally requires treatment for 6 to 8
weeks,4 and they are ineffective in 30% to 50% of patients.5,6
Faster-acting and more effective
antidepressants are needed.
A single intravenous (IV) subanesthetic dose of ketamine can
produce an antidepressant
response in hours instead of weeks, even in medication-resistant
MDD.7-16 Ketamine has
antidepressant benefit in both patients with MDD17,18 and
those with bipolar depression.19 Adverse
effects of ketamine include transient depersonalization and
derealization, among other
psychotomimetic and dissociative symptoms.20,21
Understanding the mechanism of its rapid-onset
antidepressant action may aid identification of alternative
medications that can be used orally, have
fewer adverse effects, and have less abuse potential.
We previously reported on an open pilot MDD study that
showed, consistent with glutamate
increases in rodent studies,22,23 that ketamine induces an acute
increase in ventro-medial prefrontal
cortex (mPFC) levels of the combined resonance of glutamate
and glutamine (Glx), measured with

proton magnetic resonance spectroscopy (1H MRS).24
Unexpectedly, we also observed an increase in
γ-aminobutyric acid (GABA) levels that correlated positively
with the increase in Glx levels. Preclinical
studies suggest that ketamine’s antidepressant mechanism of
action may be mediated by glutamate
activation of the glutamatergic α-amino-3-hydroxy-5-methyl-4-
isoxazolepropionic acid (AMPA)
receptors25-28 and the downstream induction of the
neurotrophin29,30 and mammalian target of
rapamycin29,30 (mTOR; also known as mechanistic TOR)
signaling pathways. An alternative
model31,32 suggests that it is not glutamate that mediates
ketamine’s antidepressant action; rather, it
is a direct consequence of ketamine's inhibitory effect on the N-
methyl-D-aspartate (NMDA)
receptors. The role of GABA is unknown, but an increase in its
level reverses the reported GABA
deficit in major depression.33-37
In the current study, we sought to determine whether the dose of
ketamine or blood levels of
ketamine and its metabolites are correlated with antidepressant
effect and adverse effects. We also
explored whether ketamine or metabolite levels correlate with
mPFC Glx or GABA levels and, in turn,
whether Glx or GABA levels mediate the acute antidepressant
or adverse effects of ketamine among
individuals with MDD. To do this, we conducted a randomized,
placebo-controlled, dose-finding,
clinical trial in patients with MDD not currently receiving
medication, who underwent MRS
measurements of mPFC Glx and GABA during the IV
administration of ketamine. Blood levels of
ketamine and metabolites were assayed after the scan.

JAMA Network Open | Psychiatry Relationship of Ketamine
Dose With Depression Symptoms in Adults With Major
Depression
12, 2020 2/14
01/21/2021
https://www.clinicaltrials.gov/ct2/show/NCT01558063
Methods
Patients
Figure 1 shows the study flow. Of the 43 patients, 5 were
unable to complete the study because of
scanner-related discomfort or technical issues. For the final
analysis, we included 38 physically
healthy patients, aged 18 to 59 years, who met the Diagnostic
and Statistical Manual of Mental
Disorders (Fourth Edition) criteria for a major depressive
episode (MDE) in the context of MDD and
scored at least 22 on the Montgomery-Åsberg Depression Rating
Scale (Table), which was only used
to establish depression severity for determini ng eligibility to
prevent inflation of baseline scores38-40
on the primary outcome measure (a 22-item version of Hamilton
Depression Rating Scale

[HDRS-22]). Patients were not taking any psychotropic
medications and had not been taking
medications likely to interact with GABA or glutamate for at
least 14 days, neuroleptics for at least 1
month, or fluoxetine for at least 6 weeks before receiving
ketamine. The detailed protocol is available
in Supplement 1.
Exclusion criteria included lifetime history of bipolar disorder,
schizoaffective disorder,
schizophrenia, or any other psychotic disorder, including MDD
with psychotic features; a first-degree
relative with bipolar disorder, schizoaffective disorder, or
schizophrenia, with the potential
participant younger than 33 years (ie, still at age of risk for a
psychotic disorder); receipt of
electroconvulsive therapy within 3 months of enrolling in the
study; history of IV drug use;
nonresponse or intolerance to ketamine (defined as participation
in another ketamine study and
reporting to us less than a robust response); pregnancy,
planning to conceive, or sexually active but
not using adequate birth control; and contraindications to
magnetic resonance imaging (MRI).
Patients who were actively suicidal were also excluded. All
patients were outpatients. All patients
were enrolled after a psychiatric and medical screening,
conducted between February 2012 through
May 2015, determined that they met the entrance criteria and
after they provided written informed
consent. The study was approved by the New York State
Psychiatric Institute institutional review
board and was completed in October 2019, before recruitment
goals were met (see details in Study
Design section). This study followed the Consolidated
Standards of Reporting Trials (CONSORT)

reporting guideline.
Figure 1. Study Flow Diagram
422 Patients assessed for eligibility
5 Allocated to and received
placebo
38 Allocated to and received
ketamine
32 Analyzed5 Analyzed
43 Randomized
379 Excluded
117 Were treatment naive
37 Had psychiatric comorbidity
38 Had lack of interest
30 Had medical comorbidity
27 Were lost to follow-up after screening
80 Had other reasons
6 Excluded
1 Discontinued intervention because of
adverse effects
4 Experienced scanner technical issues
1 Had poor quality spectra
Depression

12, 2020 3/14
01/21/2021
http://www.equator-network.org/reporting-guidelines/consort/
Study Design
Randomization and assignment of ketamine dose (ie, 0.1, 0.2,
0.3, 0.4 or 0.5 mg/kg) or placebo were
performed by the statistician. An adaptive randomization
strategy was used to optimize group size
in terms of dose response curves. The randomization was
supposed to have 11 participants per group,
but the study was stopped before recruiting goals were met
because funding ran out and an interim
analysis found robust statistical effects. Randomized ketamine
doses were shared via sealed
nontranslucent envelopes with the research pharmacy and a
clinician who was not involved in
patient study ratings. Study patients and raters were masked
until study termination unless
unmasking was clinically warranted. No patient required
unmasking in the course of the ketamine
infusion. Patients received a single 40-minute infusion and were
observed for 24 hours after
ketamine administration. All scans and data were obtained at
Columbia University Medical Center.
Prior to treatment infusion, patients underwent structural MRI

and baseline 1H MRS scans. Scan
analysis was performed on coded data sets masked to the subject
dosing and treatment response.
Patients were administered placebo or ketamine intravenously
during approximately 40 minutes. Six
1H MRS data frames of approximately 13 minutes each were
acquired: 1 prior to ketamine infusion
and 5 during and immediately after ketamine infusion. We
determined clinical response 24 hours
after ketamine administration using the HDRS-22. The masking
procedures and randomization
ensured minimal possibility of biasing based on Cochrane
criteria.41
Safety and Tolerability
Vital signs, including blood pressure and heart rate, were
monitored 5 minutes prior to ketamine
infusion, every 5 minutes during the 40-minute ketamine
infusion, and every 5 minutes after for the
duration of the 1H MRS scan or until vital signs returned to
clinically acceptable levels. Patients were
evaluated by a physician for blood pressure, psychosis and other
psychotomimetic adverse effects
(using the Brief Psychiatric Rating Scale [BRPS]), and suicidal
ideation (using the Columbia–Suicide
Severity Rating Scale) 230 minutes after the initiation of the
ketamine infusion. Four serious adverse
events occurring during study participation were reported to the
institutional review board: 1 for
Table. Demographic and Clinical Characteristics of Participants
by Assigned Intravenous Ketamine Dose
Characteristic
Mean (SD), by dose group Statistical differences

0.0 mg/kg
(n = 5)
0.1 mg/kg
(n = 5)
0.2 mg/kg
(n = 6)
0.3 mg/kg
(n = 8)
0.4 mg/kg
(n = 5)
0.5 mg/kg
(n = 9) F5,32 P value
Age, y 46.8 (12.3) 37.4 (12.3) 37.8 (8.2) 38.1 (7.2) 30.6 (9.4)
40.2 (14.5) 1.119 .37a
Women, No. (%) 2 (40) 4 (80) 5 (83) 4 (50) 3 (60) 5 (56) NA
.69b
White race, No. (%) 4 (80) 1 (20) 4 (67) 7 (88) 2 (40) 7 (78) NA
.14b
Hispanic ethnic group, No. (%) 1 (20) 1 (20) 1 (17) 0 (0) 1 (20)
2 (22) NA .84b
Age of MDD first episode onset, y 28.8 (16.9) 20.6 (10.3) 13.3
(2.7) 20.6 (8.2) 19.4 (5.6) 16.6 (8.1) 1.778 .15a
Duration of current MDE, y 5.3 (3.1) 4.1 (4.4) 13.7 (15.9) 8.1
(12.5) 8.8 (11.2) 16.2 (19.7) 0.790 .57a

Duration of MDD, y 18.0 (14.7) 16.8 (14.4) 24.6 (9.6) 17.3
(11.6) 10.9 (8.8) 23.7 (16.6) 0.876 .51a
Previous MDEs, No. 0.4 (0.5) 1.0 (1.4) 1.7 (1.9) 1.5 (2.1) 1.0
(1.4) 0.8 (0.8) 0.609 .69a
Baseline MADRS total score 32.8 (4.9) 31.0 (6.3) 28.0 (3.6)
31.1 (3.0) 32.8 (1.3) 30.9 (4.1) 0.935c .47a
Baseline HDRS-22 total score 25.0 (3.4) 25.0 (5.5) 24.2 (4.3)
25.9 (7.7) 27.2 (5.0) 27.0 (5.3) 0.290 .93a
Change in HDRS-22 total score 24 h
after ketamine infusion, %
−2.8 (3.7) −6.2 (13.0) −6.7 (7.3) −8.3 (6.3) −10.8 (6.8) −13.3
(7.9) NA NA
AUC blood level, ng/mLd
Ketamine 0.0 (0.0) 27.2 (7.0) 44.5 (18.9) 59.1 (12.2) 71.6 (16.8)
112.8 (27.9) NA NA
Norketamine 0.0 (0.0) 30.2 (17.2) 31.8 (6.8) 56.6 (18.4) 71.0
(21.8) 95.2 (25.6) NA NA
Dehydronorketamine 0.0 (0.0) 17.6 (4.8) 31.8 (11.7) 39.9 (9.2)
42.8 (9.6) 52.1 (17.5) NA NA
Abbreviations: AUC, area under the curve; HDRS-22, 22-item
Hamilton Depression
Rating Scale; MADRS, Montgomery-Åsberg Depression Rating
Scale; MDD, major
depressive disorder; MDE, major depressive episode; NA, not
applicable.
a Results of between groups analysis of variance.

b Result of Fisher exact test.
c Result for F5,31 statistic.
d Area under the curve calculated for ketamine and metabolite
blood levels as the sum
of their respective blood levels at 90 and 120 minutes
postinitiation of ketamine
infusion.
Depression
12, 2020 4/14
01/21/2021
suicide, 1 for active suicidal ideation, 1 for antidepressant
misuse, 1 for unrelated medical illness (see
eTable in Supplement 2).
Pharmacokinetic Assessments
Blood samples were collected at 90 and 120 minutes after
initiation of ketamine infusion to assay
plasma concentrations of ketamine and metabolites.24 Blood
samples were not collected for
technical reasons during the approximately 80-minute 1H MRS
acquisition. We used the sum of the
2 ketamine and metabolite levels to get a more stable
measurement of their plasma concentrations

across participants because ketamine is metabolized rapidly and
variably.42
Clinical Assessments
The 24-item HDRS was administered within 60 minutes before,
230 minutes after, and 24 hours
after initiation of ketamine infusion. We modified the 24-item
HDRS, excluding items 16 (loss of
weight) and 18 (diurnal variation) because a change in these
measures could not be assessed within
24 hours. Response was defined as percentage change on this
22-item HDRS 24 hours after ketamine
administration.
Magnetic Resonance Neuroimaging Scans
All the neuroimaging data were acquired on a GE Signa
EXCITE 3.0T MR scanner equipped with an
8-channel surface coil, as previously described.24 Briefly, a 3-
plane localizer imaging series was
obtained, followed by a 2-dimensional fast spoiled gradient-
recalled echo MRI scan in sagittal planes
(echo time, 2.1 milliseconds; repetition time, 75 milliseconds;
flip angle, 75°; field of view, 256 × 256
mm2; slice thickness, 5 mm; 8 slices) and a volumetric T1-
weighted spoiled gradient-recalled MRI scan
prescribed in the oblique axial planes parallel to the anterior
commissure–posterior commissure line
(echo time, 2.86 milliseconds; repetition time, 7.12
milliseconds; flip angle, 9°; field of view,
256 × 256 mm2; image matrix size, 256 × 256; slice thickness,
1 mm; voxel size, 1 × 1 × 1 mm3). A
voxel of 3.0 × 2.5 × 2.5 cm3 was placed in the ventral mPFC
region based on the sagittal and oblique
axial images, with the center of the posterior side of the voxel
close to the front tip of the cingulate
gyrus (eFigures 1A and 1B in Supplement 2). In vivo brain

spectra of the combined resonance of Glx
and GABA were recorded from the voxel using the standard J-
edited spin echo difference
method.43,44 Data were acquired as six 13-minute frames. The
levels of Glx and GABA in the edited
spectra were fitted in the frequency domain as previously
described (eFigure 1C in
Supplement 2)43,44 and then expressed as peak area ratio
relative to the synchronously acquired and
similarly fitted unsuppressed voxel water signal—a commonly
used45-49 method with reasonable
test-retest reliability.44 Data from 1 participant were excluded
from further analysis because of poor-
quality spectra. Details of the 1H MRS data quality assessment
criteria used to retain or reject spectra
for inclusion in group analyses can be found in previously
published supplemental online material.44
Statistical Analysis
Ketamine, norketamine, and dehydronorketamine blood levels
(ng/mL) were measured as the mean
of the levels at 90 and 120 minutes. Levels of Glx and GABA in
the mPFC were measured as the area
under the curve from 0 to approximately 42 minutes following
initiation of ketamine infusion. Clinical
improvement was measured as the percentage change in HDRS-
22 score from baseline to 24 hours
after dose. Psychotomimetic effects were measured with the
BPRS total score.
To examine the effect of ketamine dose on clinical
improvement, we fit a simple linear
regression model. Next, we fit separate simple linear regression
models to test the effect of ketamine
dose on ketamine blood level, Glx level, and GABA level. With
similar models, we explored the effect

of ketamine blood level on Glx level and on GABA level. Next,
we fit separate simple linear regression
models with clinical improvement as outcome and ketamine
blood level, Glx level, and GABA level
as independent variables. Finally, to determine whether Glx
level mediates the effect of ketamine
dose on clinical improvement, we also fit a multiple regression
model with clinical improvement as
Depression
12, 2020 5/14
01/21/2021
outcome and both ketamine dose and Glx level as independent
variables.50-52 For each analysis we

reported the test statistic value with degrees of freedom, P
value, and parameter estimate with its
95% CI.
In the analysis of the adverse effects data, we fit separate
simple linear regression models with
psychotomimetic effects as outcome and as predictors: blood
ketamine level, Glx, GABA,
norketamine, dehydronorketamine, and clinical improvement.
These analyses were repeated
separately for men and women. Data analysis was conducted in
R version 3.6.3 (R Project for
Statistical Computing) from January to March 2020. Statistical
significance was set at P < .05, and all
test were 2-tailed but not corrected for multiple comparisons
over the entire analytic set.
Results
A total of 38 individuals participated in the study, with a mean
(SD) age of 38.6 (11.2) years, 23
(60.5%) women, and 25 (65.8%) White patients. The Table
describes the patient population
demographic characteristics, depression severity, and clinical
response to each ketamine dose. The
ketamine dose and placebo treatment groups did not differ
statistically in demographic
characteristics, baseline depression severity or duration of
current episode, number of lifetime
episodes, or years since onset of MDD. Notably, the entire
patient sample had a long duration of their
current major depressive episode.
Effects of Ketamine IV Dose and Blood Level on Clinical
Improvement
Ketamine dose effects on clinical improvement are summarized

in the Table and Figure 2A. Injected
dose of ketamine had a positive relationship with clinical
improvement (t36 = 2.81; P = .008; slope
estimate, 19.80 [95% CI, 5.49 to 34.11]), as did the ketamine
blood level (t36 = 2.25; P = .03; slope
estimate, 0.070 [95% CI, 0.007 to 0.133]). Metabolite levels did
not correlate statistically with
clinical improvement (norketamine: t35 = 1.88; P = .07; slope
estimate, 0.07 [95% CI, −0.006 to
0.146]; dehydronorketamine: t35 = 1.13; P = .27; slope
estimate, 0.075 [95% CI, −0.060 to 0.211]).
Relationship of Ketamine Dose With Blood Level
Ketamine dose correlated positively with ketamine blood level
(t36 = 12.08; P < .001; slope estimate,
10.5 [95% CI, 175.2 to 245.9]). The results of this test are
illustrated in eFigure 2 in Supplement 2.
Figure 2. Changes in Modified 22-Item Hamilton Depression
Rating Scale (HDRS) Score 24 Hours After Ketamine
Intravenous Dose
–55
5
Ch
an
ge
in
sc
or
e,

% –15
–35
Predose score Day 1 score
Percentage change in 22-item HDRS total scoreA
10
0
Ch
an
ge
in
H
DR
S
to
ta
l s
co
re
–10
–20
–30

–8.8 –8.5 –8.3 –8.0 –7.8 –7.5
Change in Glx level
Association of change in 22-item HDRS total score
and Glx level change
B
10
0
Ch
an
ge
in
H
DR
S
to
ta
l s
co
re
–10
–20
–30

–8.0 –7.8 –7.6 –7.4 –7.2
Change in GABA level
Association of change in 22-item HDRS total score
and GABA level change
C
0.0
Ketamine dose, mg/kg
0.1
0.2
0.3
0.4
0.5
GABA indicates γ-aminobutyric acid; Glx, glutamate and
glutamine.
Depression
12, 2020 6/14
01/21/2021
https://jama.jamanetwork.com/ar ticle.aspx?doi=10.1001/jamanet

Effects of Ketamine Blood Level on Glx and GABA Levels
The injected dose of ketamine showed a negative relationship
with Glx (t33 = −4.120; P < .001; slope
estimate, −1.088 [95% CI, −1.626 to −0.551]) and, in a separate
model, with GABA (t33 = −4.450;
P < .001; slope estimate, −0.714 [95% CI, −1.041 to −0.388]).
The ketamine blood level also had a
negative relationship with Glx (t33 = −4.087; P < .001; slope
estimate, −0.005 [95% CI, −0.007 to
−0.002]) (Figure 3B) and GABA (t33 = −4.334; P < .001; slope
estimate, −0.003 [95% CI, −0.004 to
−0.002]) (Figure 3C).
Effects of Glx and GABA on Clinical Improvement
We found a positive relationship between Glx and clinical
improvement (t33 = −2.400; P = .02; slope
estimate, −9.85 [95% CI, −18.2 to −1.50]) (Figure 2B). When
both ketamine blood level and Glx were
used as predictors in a multiple regression analysis, neither the
effect of Glx on clinical improvement
(t32 = −1.417; P = .17; slope estimate, −7.153 [95% CI,
−17.436 to 3.130]) nor the effect of ketamine
blood level on clinical improvement (t32 = 0.922; P = .36; slope
estimate, 0.037 [95% CI, −0.045 to
0.119]) remained significant. Similarly, when both injected
ketamine dose and Glx were used in a
multiple regression analysis, neither the effect of Glx on
clinical improvement (t32 = −1.103; P = .28;
slope estimate, −5.465 [95% CI, −15.554 to 4.624]) nor the
effect of injected ketamine dose on
clinical improvement (t32 = 1.519; P = .14; slope estimate,
14.053 [95% CI, −4.787 to 32.893])

remained significant. Although Glx had a significant positive
relationship with GABA (t33 = 8.117;
P < .001; slope estimate, 0.510 [95% CI, 0.382 to 0.638])
(Figure 3A), GABA was not associated with
clinical improvement (t33 = −1.552; P = .13; slope estimate,
−10.67 [95% CI, −24.66 to 3.32])
(Figure 2C).
Adverse Effects
Psychotomimetic effects were measured with the BPRS.
Ketamine blood level was not related to
BPRS score when analyzing the full sample (t23 = 1.084; P =
.29; estimated slope, 0.29 [95% CI,
−0.26 to 0.084]). In men only, ketamine blood level had a
positive relationship with BPRS score
(t5 = 2.606; P = .048; estimated slope, 0.093 [95% CI, 0.001 to
0.186]), while there was no effect in
women (t16 = −0.362; P = .72; estimated slope, −0.013 [95%
CI, −0.086 to 0.061]). In men, both
norketamine and dehydronorketamine blood levels had a
positive relationship with BPRS score
(norketamine: t5 = 3.944; P = .01; estimated slope, 0.139 [95%
CI, 0.049 to 0.230];
dehydronoketamine: t5 = 2.589; P = .049; estimated slope,
0.167 [95% CI, 0.001 to 0.334]).
Figure 3. Correlations Between Glutamate and Glutamine (Glx),
γ-Aminobutyric Acid (GABA), and Ketamine Blood Levels
–7.2
GA
BA
le
ve

l c
ha
ng
e
–7.4
–7.6
–7.8
–8.0
0 20 40 60 80 100 120 140 160
Correlation between GABA level change and
ketamine blood level
C
–7.2
GA
BA
le
ve
l c
ha
ng
e

–7.4
–7.6
–7.8
–8.0
–8.8 –8.5 –8.3 –8.0 –7.8 –7.5
Glx level change
Correlation between GABA and Glx level changes A
0 20 40 60 80 100 120 140 160
–7.6
–8.0
–7.8
Gl
x
le
ve
l c
ha
ng
e
–8.3

–8.5
–8.8
Ketamine blood level, ng/mL Ketamine blood level, ng/mL
Correlation between Glx level change and
ketamine blood level
B
0.0
Ketamine dose, mg/kg
0.1
0.2
0.3
0.4
0.5
Level change was measured as area under the curve 0 to
approximately 42 minutes following initiation of ketamine
infusion.
Depression
…
184 | wileyonlinelibrary.com/journal/jocn J Clin Nurs.
2020;29:184–194.© 2019 John Wiley & Sons Ltd

Received: 10 June 2019 | Revised: 30 August 2019 |
Accepted: 29 September 2019
DOI: 10.1111/jocn.15076
O R I G I N A L A R T I C L E
Sleep and fatigue in newly graduated nurses—Experiences and
strategies for handling shiftwork
Majken Epstein BSc1 | Marie Söderström PhD, Licensed
Psychologist1,2 |
Maria Jirwe PhD, Associate Professor, Registered Nurse3,4 |
Philip Tucker PhD,
Associate Professor5,6 | Anna Dahlgren PhD1
1Division of Psychology, Department of
Clinical Neuroscience, Karolinska Institutet,
Stockholm, Sweden
2Stressmottagningen/Stress clinic,
Stockholm, Sweden
3Department for health promoting
science, Sophiahemmet University,
Stockholm, Sweden
4Division of Nursing, Department
of Neurobiology, Care Sciences and
Society, Karolinska Institutet, Huddinge,
Sweden
5Stress Research Institute, Stockholm
University, Stockholm, Sweden
6Department of Psychology, Swansea
University, Swansea, UK
Correspondence
Anna Dahlgren, Department of Clinical
Neuroscience, Division of Psychology,

Karolinska Institutet, Nobels väg 9, 171 65
Solna, Stockholm, Sweden.
Email: [email protected]
Funding information
AFA Försäkring, Grant/Award Number:
150024
Abstract
Aims and objectives: To explore newly graduated nurses'
strategies for, and experi-
ences of, sleep problems and fatigue when starting shiftwork. A
more comprehensive
insight into nurses' strategies, sleep problems, fatigue
experiences and contributing
factors is needed to understand what support should be
provided.
Background: For graduate nurses, the first years of practice are
often stressful, with
many reporting high levels of burnout symptoms. Usually,
starting working as a nurse
also means an introduction to shiftwork, which is related to
sleep problems. Sleep
problems may impair stress management and, at the same time,
stress may cause
sleep problems. Previously, sleep problems and fatigue have
been associated with
burnout, poor health and increased accident risk.
Design and Methods: Semi‐ structured interviews were
conducted with nurses
(N = 11) from four different Swedish hospitals, and qualitative
inductive content
analysis was used. The study was approved by the Regional
Ethical Review Board in
Stockholm. The COREQ checklist was followed.
Results: Many nurses lacked effective strategies for managing
sleep and fatigue in re-

lation to shiftwork. Various strategies were used, of which some
might interfere with
factors regulating and promoting sleep such as the homeostatic
drive. Sleep prob-
lems were common during quick returns, often due to
difficulties unwinding before
sleep, and high workloads exacerbated the problems. The
described consequences
of fatigue in a clinical work context indicated impaired
executive and nonexecutive
cognitive function.
Conclusion: The findings indicate that supporting strategies and
behaviours for sleep
and fatigue in an intervention for newly graduated nurses
starting shiftwork may be
of importance to improve well‐ being among nurses and
increase patient safety.
Relevance to clinical practice: This study highlights the
importance of addressing
sleep and fatigue issues in nursing education and work
introduction programmes to
increase patient safety and improve well‐ being among nurses.
K E Y W O R D S
fatigue, newly graduated nurses, patient safety, shiftwork, sleep
https://orcid.org/0000-0001-8397-5986
https://orcid.org/0000-0001-7676-7919
https://orcid.org/0000-0003-4570-4047
https://orcid.org/0000-0002-8105-0901
mailto:
https://orcid.org/0000-0001-8252-3961
mailto:[email protected]
http://crossmark.crossref.org/dialog/?doi=10.1111%2Fjocn.1507
6&domain=pdf&date_stamp=2019-10-31

| 185EPSTEIN ET al.
1 | INTRODUC TION
Approximately 20% of all Swedish nurses experiences very high
levels of burnout symptoms at some point during the first years
of
practice (Rudman & Gustavsson, 2011). In addition to stressors
that
are evident for the whole nursing population, such as high
work-
load, staff shortage and emotional demands (McVicar, 2003),
newly
graduated nurses are facing specific challenges associated with
the
adaptation to a new professional role, a phenomenon referred to
as
a transition shock (Duchscher, 2009). When developing methods
to
facilitate the nurse's transition from education into working life,
a
variety of stressors at both the organisational and individual
level
have to be considered (Sun, Ji, Zhou, & Liu, 2019).
The stress response promotes adaptation through bodily and
behavioural changes, but may have damaging effects if
prolonged
or repeated without sufficient recovery in between (McEwen,
2004). Previously, incomplete recovery has been suggested to
mediate the relation between stressful working conditions and
health impairment (Geurts & Sonnentag, 2006). For many,
starting
working as a nurse also means an introduction to shiftwork,

which
inevitably affects opportunities for sleep and recuperation due
to interference with the circadian and homeostatic regulation of
sleep (Åkerstedt, 2003). Not surprisingly, sleep problems are
more
common among nurses working on shift schedules compared to
nurses working regular daytime (McDowall, Murphy, &
Anderson,
2017). In a cohort of Swedish nurses, subjective sleep quality
was
shown to decrease from the last semester of the education and
during the first 3 years of employment (Hasson & Gustavsson,
2010). Sleep problems and fatigue among nurses may threaten
both the nurses' own health and patient safety (Hughes &
Rogers,
2004; McEwen, 2006).
2 | BACKGROUND
Sleep deprivation is a stressor for the brain and body (McEwen,
2006), and insufficient sleep has been identified as a main risk
factor for clinical burnout (Söderström, Jeding, Ekstedt, Perski,
&
Åkerstedt, 2012). At the same time, stress is known to
negatively
influence sleep (Linton et al., 2015). High workload and high
per-
ceived stress at work have been associated with heightened
stress
at bedtime and shorter sleep (Dahlgren, Kecklund, & Åkerstedt,
2005). It is possible that sustained physiological activation
partly
explains the impact of stress and workload on sleep, but perse-
verative cognition is also likely to play a role (Brosschot,
Gerin, &
Thayer, 2006).

Shiftwork, in general, is associated with sleep problems and
fatigue (Kecklund & Axelsson, 2016). A key issue is the timing
of
the shifts. Night shifts and early morning shifts have been
associ-
ated with more sleep problems and fatigue, compared to evening
shifts (Åkerstedt, 2003). Recent studies have shown that shift
combinations involving so‐ called “quick returns,” that is less
than
11 hr between shifts, are associated with shorter sleep, impaired
sleep quality, increased sleepiness and fatigue (Vedaa et al.,
2015).
The frequency of quick returns is also associated with difficul -
ties unwinding (Dahlgren, Tucker, Gustavsson, & Rudman,
2016).
Two more or less ineluctable consequences of disturbed sleep
are
sleepiness and fatigue. Fatigue is a major safety hazard and has
been associated with impaired performance, higher error rates
and reduced safety (Dawson & McCulloch, 2005).
2.1 | Theoretical framework
Given the vital role of sleep and recovery in the relationship be -
tween stress and development of illness (Geurts & Sonnentag,
2006; McEwen, 2004; Söderström et al., 2012), effective strate-
gies for sleep and recovery are hypothesised to be crucial in
pre-
venting the development of stress‐ related illnesses (Colombo &
Cifre Gallego, 2012). They are likely to be particularly
important
for newly graduated nurses who are exposed to a large number
of
stressors in their daily work at the same time as they are

starting
to work shifts. Strategies for managing fatigue are also of great
importance, not least considering the potential impact on patient
safety.
2.2 | Aim
Little is known about the actual strategies for managing sleep
and
fatigue that nurses adopt when they start working shifts. Such
knowledge, together with more comprehensive understanding of
new nurses' sleep problems and the nature of their fatigue
problems,
is important to know which support (or interventions) nurses
need
when starting out in their new career. By focusing on newly
gradu-
ated nurses and their challenges, appropriate support can be put
in
place before more serious problems arise. Thus, the aim of the
cur-
rent study was to explore the strategies used by newly graduated
nurses for managing sleep and fatigue problems, identify which
fac-
tors they experienced as contributing to sleep problems and
ascer-
tain the nature of the fatigue problems that they experience. In
this
study, a newly graduated nurse is defined as a nurse in their
first year
of employment.
What does this paper contribute to the wider global
clinical community?
• Newly graduated nurses lack effective strategies for

sleep and fatigue, and the strategies used are often
counterproductive.
• Newly graduated nurses experience cognitive deficits
due to fatigue, which may have implications for patient
safety.
• Newly graduated nurses need to learn effective strate-
gies for managing sleep and fatigue, to promote patient
safety and nurses' health.
186 | EPSTEIN ET al.
3 | METHODS
3.1 | Participants
Eleven newly graduated nurses (ten women, one man) between
22–51 years old (M = 29.1, S = 8) were included in the study.
The
nurses were recruited from four, university and county
hospitals.
The inclusion criterion was a maximum of 1 year's employment
as
a registered nurse. In Sweden, the education for registered
nurses
consists of about 60% theoretical education and 40% clinical
prac-
tice (Ulfvarson, Oxelmark, & Jirwe, 2018). The sampling was
pur-
posive, and recruitment was made in two ways; either through a
lecture about working hours led by the researchers, included in
the
hospitals' introduction programmes for nurses; or through infor -

mation disseminated by the hospitals' HR departments. All
nurses
who signed up for the study (N = 17) were contacted by e‐ mail
or
telephone to make an appointment for the interview. Eleven
nurses
answered and agreed to participate in the study (see Table 1).
The study was approved by the Regional Ethical Review Board
in Stockholm (2016/1395‐ 31/2). Before starting each interview,
participants gave written informed consent. It was emphasised
that
participation in the study was voluntary and that the participant
could cancel the interview at anytime or choose not to answer
some
questions without giving further explanation. No compensation
was
given for participation. All data were stored on protected
servers
accessible only for researchers involved in the project.
3.2 | Materials
Semi‐ structured interviews were conducted by either MS
(female) or
AD (female) and lasted approximately 45 min. The interviews
were held
between October 2016–April 2017. The participants had not met
the
researcher before, apart from those who had attended the lecture
at
the introduction programme. Participants were told that the aim
of the
interview was to gain a deeper insight into the participant's
work situa-
tion with focus on work hours and recuperation, in order to gain

knowl-
edge about how to design an intervention for newly graduated
nurses.
Interviews were conducted either by telephone (eight nurses) or
face‐
to‐ face in the vicinity of the introduction programme (three
nurses),
focusing on sleep and fatigue in relation to shiftwork. No one
but the
participant and the researcher was present during the interview.
The
participants were told that the results would be presented at a
group
level only and that no individual answers would be
communicated to
managers. Specific questions addressed the nurses' experiences
of
sleep and fatigue in connection to different shifts (morning,
evening,
night and quick returns). Strategies used for recovery, such as
managing
sleep and fatigue when working the different shifts, were also
explored.
Also, more general questions like “Do you experience sleep
problems?”
“Are you sometimes feeling fatigued or exhausted at work?”
and “How
do you recover during spare time?” were used and
complemented by
appropriate follow‐ up questions. The questions were based on,
and
further developed from, a previous interview guide (Frögeli,
Rudman,
Ljótsson, & Gustavsson, 2018). During the last interviews, no
new in-

formation was identified and the research team considered data
satu-
ration to have been achieved in relation to the content of the
data, that
is when no new information was obtained from the interviews.
Sleepiness and fatigue can be described as two interrelated, but
distinct, phenomena. Sleepiness could be broadly defined as the
“drive” to fall asleep. Fatigue, on the other hand, could be
defined as
a subjective experience of overwhelming tiredness, lack of
energy
or exhaustion, that could be alleviated after rest, activity or
stress
management. However, the terms are commonly used
interchange-
ably or merged under the broader term “tiredness” (Shen,
Barbera, &
Shapiro, 2006). In this study, the term fatigue was used as a
broader
concept including also “sleepiness” and “tiredness”, since it is
likely
that the participating nurses did not make any distinction when
de-
scribing their experiences.
3.3 | Analysis
All interviews were audio‐ recorded, transcribed and analysed
using
inductive content analysis (Elo & Kyngäs, 2008). The analysis
was
not software‐ assisted. The analysis process was conducted in
three
phases: preparation, organising and reporting.

TA B L E 1 Background information
about participants
Participant Gender Age Workplace
Employment
as nurse
(months) Shift schedule
1 Female 29 Geriatrics 4 Morning and evening
2 Male 26 Psychiatry 4 Morning, evening and night
3 Female 35 Stroke 4 Morning and evening
4 Female 25 Infection 9 Morning, evening and night
5 Female 29 Palliative care 5 Morning and evening
6 Female 27 (Missing) 4 Morning and evening
7 Female 24 Infection 11 Morning, evening and night
8 Female 51 Rehabilitation 5 Morning and evening
9 Female 22 Neonatal care 5 Morning, evening and night
10 Female 26 Patient hotel 12 Morning and evening
11 Female 26 Hand surgery 12 Morning, evening and night
| 187EPSTEIN ET al.
In the preparation phase, the transcripts were read several times

to make sense of the whole and units of analysis were selected.
In
this study, the unit of analysis was, as suggested by Graneheim
and
Lundman (2004), the interview as a whole. The data were then
or-
ganised in three steps: open coding, creation of categories and
ab-
straction. During the open coding, notes and headings were
written
in the text to describe all aspects of the content. The headings
were
then put into groups with similar content, and categories were
gen-
erated. At the last step, abstraction, the subject under study was
described by generating subcategories and naming them using
con-
tent‐ characteristic words. The subcategories were grouped
together
into generic categories, and generic categories were grouped
into
wider main categories (see Table 2).
To increase the trustworthiness, the data collection, analysis
and
presentation of the results have involved a continuous process
of
discussions within the research group. The varied professional
back-
ground and expertise in the research group was such that the re-
searchers' pre‐ understandings were unlikely to affect data
collection
or analysis. Hence, the risk of preconceived ideas and
conclusions in-
truding was limited. Also, the questions asked during the
interviews

were open‐ ended and the respondents were asked to clarify
their re-
sponses, so as to minimise reinterpretation of the answer by the
in-
terviewer. MJ has extensive knowledge and experience of
qualitative
research/analysis and guided the others in the research team.
The anal-
ysis was initially conducted by ME and AD, with and through
regular
discussions with MS and MJ, until common agreement was
reached. To
increase credibility of the results, MJ read all the interview
transcripts
and confirmed the analysis after it was completed. Many
categories
are exemplified with literal quotes from the nurses, which
further in-
creases the credibility. The article adheres to the consolidated
criteria
for reporting qualitative research (COREQ) checklist, see
Appendix S1
(Tong, Sainsbury, & Craig, 2007).
4 | RESULTS
Analyses led to four main categories: (a) factors contributing to
sleep
problems, (b) strategies for sleep, (c) experiences of fatigue and
(d)
strategies for fatigue. Each main category consists of different
ge-
neric categories, of which some consist of subcategories (Figure
1).

4.1 | Factors contributing to sleep problems
The analyses identified two generic categories characterising
the
nurses' experiences of factors contributing to sleep problems:
(a)
shift factors and (b) cognitive arousal (with two subcategories).
4.1.1 | Shift factors
Sleep quality was commonly discussed in relation to type of
shift/
shift sequence. Most nurses experienced impaired sleep quality
in connection with shift combinations featuring an evening shift
TA B L E 2 Example of coding and categorisation
Data from interviews Codes from interviews Subcategory
Generic category Main category
It's harder when I'm on an evening‐ day shift, but
of course this is about winding down, but I find it
harder to switch off from work when I get home.
I just think, I have to do this tomorrow, and this,
and this, and this … That doesn't happen when I'm
on day‐ day shifts, because then I can let go in a
different way. (Nurse 4)
Hard to switch off, thinking about
what has to be done tomorrow
Anticipatory stress Cognitive arousal Factors contrib-
uting to sleep
problems
Mainly if you've been working an evening shift

and then you have to work in the day. Then I find,
well, I always sleep really badly. So it's a bit like,
you feel that you sleep and then you have to get
back to work, and if it was a busy night you sort
of know, “I can't forget that,” and things pop up in
my head, like there are certain things you have to
do. (Nurse 7)
Things that I have to do the next
day pop up in my head
Thinking about everything and then winding down
at home is incredibly difficult. The only thing buzz-
ing around in my head is did I do the right thing,
did I give the right medication, things like that, and
then I dream about these things. (Nurse 3)
Things like “did I do the right thing,”
“did I give the right medication”
are buzzing around in my head
Ruminative
thinking
If you compare with my previous workplace, that's
a bit why I resigned from my previous workplace,
because it was such an incredibly stressed work-
place. And there I sort of felt that it was almost
impossible to wind down, because there was so
much happening during the days, and you weren't
sure, did I do everything I was supposed to do.
(Nurse 11)
It was almost impossible to unwind,
I was not sure if I had done every-
thing I was supposed to

followed by a morning shift (hereafter referred to as “quick
returns”).
While some stated that sleep between the evening and the morn-
ing shift was always bad, a few noted that high workload during
the
evening shift worsened subsequent sleep.
Also, sleep duration was discussed in connection with shift se-
quence. The majority noted that quick returns were associated
with
shortened sleep duration. For many, the already short time
available
for sleep became even shorter due to difficulties unwinding, and
consequently a longer sleep latency. A few also experienced
shorter
sleep duration before regular morning shifts.
The majority of nurses working night shifts expressed dissatis-
faction with their sleep in relation to night work.
4.1.2 | Cognitive arousal
Cognitive arousal was identified as an important cause of sleep
problems, highlighted by most nurses. Worry or persistent
thoughts
in the evening, particularly related to work, often led to
problems
unwinding before sleep. This was especially common in relation
to
quick returns. Two main types of cognitive arousal were
described:

ruminative thinking and anticipatory stress. A majority noted
that high
workload during the previous or upcoming shift exacerbated
rumina-
tion and anticipation processes, and worsened problems
unwinding.
Ruminative thinking
Some nurses were often worrying or thinking about things that
had
happened at work, which impaired unwinding. This was, for
example,
expressed as persistent thoughts about a particular patient or
wor-
rying about not having done things correctly:
Thinking about everything and then winding down
at home is incredibly difficult. The only thing buzzing
around in my head is did I do the right thing, did I give
the right medication, things like that, and then I dream
about these things.
(Nurse 3)
Anticipatory stress
In relation to quick returns, some respondents also reported that
an-
ticipatory stress, such as thinking or worrying about the next
day's
work, impeded unwinding. This was typically expressed as
“think-
ing about what has to be done tomorrow” or as a feeling of
already
“being mentally at work the next day.” Some respondents

pointed
out that merely thinking about the shorter time available for
sleep
was stressful.
And if there's something in particular at work, you
know you've got a lot of patients or some patients
who sort of require a lot of attention, maybe that's
something that you lie awake thinking about, and then
sometimes you might not get to sleep until one or two
in the morning. (…) And because you then have to get
up so early the following morning, you start preparing
for it and sort of start thinking about what you'll be
doing during the day ahead.
(Nurse 2)
4.2 | Strategies for sleep
The analyses led to two generic categories of sleep strategies:
(a)
circadian rhythm and homeostasis and (b) unwinding (with two
subcategories).
4.2.1 | Circadian rhythm and homeostasis
A few nurses reported they were trying to keep regular sleeping
hours, and thus a stable circadian rhythm, despite irregular work
hours. Others reported trying to adjust the circadian rhythm to
their
schedule, for example through preparing for a morning shift by
get-
ting up earlier in the mornings 2 days in advance, despite not
work-
ing those mornings. Before night shifts, nurses reported
strategies

for rotating the rhythm forward by staying up late the preceding
night and then sleeping as long as possible in the morning
before the
F I G U R E 1 Newly graduated nurses' sleep and fatigue
experiences and strategies
Factors contributing to sleep
problems
Shift factors Cognitive arousal
Ruminative
thinking
Anticipatory
stress
Strategies for sleep
Circadian rhythm
and homeostasis Unwinding
General
unwinding
Detaching from
work
Experiences of fatigue
Manifestations of
fatigue
Cognitive
manifestations

Emotional
manifestations
Physical
manifestations
Temporal aspects
Strategies for fatigue
Proactive
strategies
Reactive
strategies
| 189EPSTEIN ET al.
night shift. When turning back to day or evening shifts after
night
work, two nurses described a strategy of setting the alarm
earlier
in the afternoon, to shorten the sleep and increase sleepiness in
the
evening.
4.2.2 | Unwinding
Nurses used different unwinding strategies to facilitate sleep:
(a)
general unwinding and (b) detaching from work.
General unwinding

Before sleep, many nurses were undertaking behaviours aimed
at
unwinding and relaxation, such as listening to music, watching
TV,
having a shower or using a breathing exercise. Some nurses de-
scribed that they usually stayed up for a while after an evening
shift,
to unwind before bedtime, but avoided this during quick returns.
However, two nurses used the strategy of staying up a while
dur-
ing quick returns; one had learned by experience that this made
her
sleep better:
In the beginning I think I tried to sort of go to bed as
soon as I got home, but I realised that that wouldn't
work. (…) I usually get home and, well, then perhaps I'll
get something to eat or I'll lie down and read or watch
TV. I wind down a bit and don't go to bed straight
away. (…) Perhaps I'd get to sleep sooner if I went
straight to bed, but I think maybe it would be slightly
worse quality of sleep.
(Nurse 10)
Detaching from work
Most nurses reported that they sometimes found it hard to
detach
from thoughts of work during leisure time and that this
sometimes
disturbed sleep. Different strategies were used to facilitate
detach-
ment. Some tried to distract themselves through focusing on
other

things, such as TV or mobile phone. Other strategies included
just
trying to think about something else and phoning a colleague.
Some
reported making a phone call from home to the ward, to ensure
that
everything was alright. One nurse had a strategy of telling her
col-
leagues (before leaving work) to call her if something seemed
un-
clear when she had left. Another had a strategy of writing
reminders
to herself while at home when she started thinking about things
to
do at work the next day.
Two nurses usually experienced problems unwinding from
thoughts of work during quick returns and lacked strategies for
han-
dling it. Another nurse reported that she always lacked
strategies
when thoughts of work occupied her mind.
4.3 | Experiences of fatigue
The experiences of fatigue consisted of two generic categories:
(a)
manifestations of fatigue (with three subcategories) and (b)
temporal
aspects.
4.3.1 | Manifestations of fatigue
Three subcategories of fatigue manifestations were identified:
cog-
nitive, emotional and physical manifestations. The majority of

the
nurses highlighted that fatigue was more noticeable during
certain
periods of high workload. These were, for example, complex or
highly emotional situations, bed crowding or unexpected
situations
with many things happening at the same time. In contrast, some
nurses experienced more fatigue during low workload or
inactivity.
Cognitive manifestations
A majority of the nurses reported various kinds of cognitive
manifes-
tations of fatigue. Some experienced problems concentrating,
for in-
stance during shift handovers; others described memory
difficulties,
such as problems remembering the care plan or appointed times
for
medication. Also problems prioritising, making decisions or
keeping
track of the overall picture were described.
When you're calculating medication, or performing
medical techniques, maybe taking samples, or when
you really do have to focus a bit more. I can feel
there's something missing. Then I can't focus as well,
and I have to prepare a medication. And it's important
not to make a mistake.
(Nurse 9)
Emotional manifestations
Nurses also experienced emotional manifestations of fatigue,

for ex-
ample feelings of being more emotionally sensitive, more easily
an-
noyed, unengaged or not as happy as usual. Also, feelings of
shame
were reported in connection to fatigue:
It is hard to keep up with everything. I lose… I can for-
get what was planned for a patient if I'm tired, so I can
forget the entire plan, even though we've done the
rounds and have discussed and planned. If someone
asks me something, I don't have a clue. (…) It's almost
embarrassing, because you yourself think that you
should know.
(Nurse 1)
Physical manifestations
For some nurses, fatigue was also manifested in physical
symptoms,
like headache, dizziness, feeling cold or physically exhausted.
4.3.2 | Temporal aspects
Fatigue varied with time of day and was dependent on type of
shift.
In relation to morning shifts, many nurses described fatigue at
the
beginning of the shift, while others experienced more fatigue in
the
afternoon. During evening shifts, only a few nurses experienced
fatigue. The majority described a period of severe fatigue
during
the early morning hours of the night shifts. Some also reported
a

sustained feeling of exhaustion following a night shift. During
quick
returns, while some nurses experienced fatigue at the beginning
of
the morning shift, the majority reported the most severe fatigue
afterwards:
It usually comes afterwards, that you're sort of struck
that… …
Dow
AJSLP
Research Article
aCommunicat
Education an
Corresponden
Editor-in-Chi
Editor: Carla
Received Mar
Revision rece
Accepted Jan
https://doi.org
Publisher Not
Practice for D
Amer

nloaded from:
Exploring the Cultural Validity of Parent-
Implemented Naturalistic Language
Intervention Procedures for Families
From Spanish-Speaking Latinx Homes
Lauren M. Cycyka and Lidia Huertaa
Purpose: This study addressed the cultural, linguistic, and
contextual validity of parent-implemented naturalistic
language interventions for young children from Latinx homes.
Parents’ perspectives on the acceptability of commonly
delivered intervention procedures were explored.
Method: Thirty-seven parents from Spanish-speaking
Latinx backgrounds with children under the age of 6 years
participated. Four focus groups were completed. Parents
responded to 14 procedures regarding the intervention
implementers, settings, activities, strategies, and language.
Structural and emergent coding was used to explore
procedural acceptability and parents’ rationales for perceiving
each procedure as acceptable, not acceptable, or neutral.
Results: Substantial intracultural variability in parents’
acceptance of specific procedures and the reasons for
ion Disorders and Sciences, Department of Special
d Clinical Sciences, University of Oregon, Eugene
ce to Lauren M. Cycyk: [email protected]
ef: Julie Barkmeier-Kraemer
Wood
ch 26, 2019
ived August 5, 2019
uary 13, 2020
/10.1044/2020_AJSLP-19-00038
e: This article is part of the Forum: Innovations in Clinical
ual Language Learners, Part 2.

ican Journal of Speech-Language Pathology • Vol. 29 • 1241–
1259 • August
https://pubs.asha.org CUNY, Lehman College - Library, Acq
Div o
their perspectives was observed. Parents’ perspectives
evinced both individualist and collectivist orientations
toward child language development. Several suggestions
regarding promising adaptations for early language
interventions that may overlap with evidence-based
parent-implemented naturalistic language intervention
procedures emerged.
Conclusion: The findings highlight the variability within the
Latinx community that is likely to impact the cultural validity
of early language interventions for children and families
from this background. Considerations for enhancing
interventions to achieve cultural congruency and promote
child outcomes are provided.
Supplemental Material: https://doi.org/10.23641/asha.
12315713
C
hildren from Latinx1 backgrounds are a large and
growing population served by speech-language
pathologists (SLPs) in early intervention. Approx-
imately one in four children in the United States today is
Latinx, and this proportion is expected to increase to one
in three children by the year 2050 (Federal Interagency
Forum on Child and Family Statistics, 2017). Disability
prevalence studies suggest that between 13% and 20% of
children, regardless of ethnicity, will present with signifi -
cant delay or difficulties in their language development
before 6 years of age (Centers for Disease Control and
Prevention, 2015; Reilly et al., 2010; Zubrick et al., 2007).
Because early difficulties with language development
hinder children’s future academic and social development

(e.g., Duff et al., 2015; Hammer et al., 2017), evidence-
based language interventions provided before the age of
6 years are highly recommended. Thus, the purpose of this
study was to explore the validity of parent-implemented
naturalistic language interventions (PI-NLIs) in the con-
text of Latinx families. With this information, SLPs will be
better prepared to meet the legal and professional mandates
that guide early interventions.
According to federal law (Individuals with Dis-
abilities Education Act [IDEA], 2004) and professional
guidelines in early intervention (American Speech-Language-
Hearing Association [ASHA], 2008, 2017; Division for
Early Childhood of the Council for Exceptional Children
[DEC], 2014), interventions for language disorders must
1The inclusive term “Latinx” is used throughout this article as a
gender-neutral substitution for Latino and Latina to refer to
individuals
of North American, South American, Cuban, Dominican, Puerto
Rican,
and Spanish descent.
Disclosure: The authors have declared that no competing
interests existed at the time
of publication.
2020 • Copyright © 2020 American Speech-Language-Hearing
Association 1241
n 12/23/2020, Terms of Use:
https://pubs.asha.org/pubs/rights_and_permissions
https://doi.org/10.23641/asha.12315 713
https://doi.org/10.23641/asha.12315713
https://doi.org/10.1044/2020_AJSLP-19-00038

Dow
be responsive to the cultural and linguistic backgrounds
of children and their families. This means that interven-
tions are reviewed for their sociocultural appropriateness
and modified when needed to align with the cultural per-
spectives of families, their use of home language(s), and the
everyday contexts of their lives. SLPs cannot assume that
existing interventions will meet the needs of all families.
Consulting families about their beliefs, values, and prac-
tices related to early language development and collabo-
rating to support family priorities in interventions avoid
this assumption. Working with families to identify cultur-
ally and linguistically responsive approaches also ensures
that the interventions SLPs provide are family centered, as
required by law (IDEA, 2004) and widely considered best
practice in early intervention (ASHA, 2008; DEC, 2014).
Because PI-NLIs are common to early intervention, SLPs
need access to information that helps to consider the
relevance of these interventions with Latinx families and
supports responsive and family-centered services.
PI-NLIs
“PI-NLIs” is an umbrella term that refers to inter-
ventions in which parents learn to deliver specific language-
facilitating strategies to their children within interactions
across daily life. Examples include prelinguistic milieu
teaching, enhanced milieu teaching, focused stimulation,
and the Hanen Parent Program. In this approach, the
parent is the primary interventionist (as opposed to the
SLP), and the naturally occurring, everyday interactions
shared by the parent and child form the intervention con-
text. Teaching parents to become interventionists is based
on the premise that children’s early development is best
fostered by the individuals with whom they are closest
(Bronfenbrenner, 1979; Phillips & Shonkoff, 2000). The

focus on parent–child interactions is supported by a large
body of literature linking parental language input to early
child language outcomes (e.g., Zauche et al., 2016). Fur-
thermore, these interactions are thought to be natural and
frequent for young children, thereby providing ample op-
portunities to practice functional communication.
The effectiveness of PI-NLIs for supporting children
with language concerns and their parents from non-Latinx
backgrounds is well established. Two meta-analyses have
found that PI-NLIs enhance the expressive vocabulary and
general oral language abilities of young children with lan-
guage disorders (Heidlage et al., 2020; Roberts & Kaiser,
2011). Roberts and Kaiser (2011) also found that children’s
receptive language abilities improved as a result of PI-NLIs;
however, this finding has not been consistent (Heidlage
et al., 2020). Significant advances in parents’ responsive-
ness and use of language models with their children follow -
ing participation in PI-NLIs have also been noted (Roberts
& Kaiser, 2011; Te Kaat-van den Os et al., 2017). In addi-
tion, there is some evidence that the gains made by chil-
dren and their parents generalize to untrained contexts and
are maintained over time (Akamoglu & Meadan, 2018).
1242 American Journal of Speech-Language Pathology • Vol. 29
• 124
nloaded from: https://pubs.asha.org CUNY, Lehman College -
Library, Acq Div o
Yet, the vast majority of this research has taken place
with families of Anglo-European descent; Latinx families
are rarely included. For example, a recent review of
21 PI-NLI studies published between the years 2000 and
2016 identified only five that included Latinx families—a
total of 10 participants across all five studies (Akamoglu &
Meadan, 2018). Not included in this review were studies
by Ijalba (2015) and Peredo et al. (2018), which specifically

targeted mothers who were Latina. Ijalba taught 12 mothers
of 3-year-old children with language delays to facilitate
language within routines (qualifying this study as a PI-NLI)
and when using interactive picture books. Peredo et al.
trained three mothers to use language facilitation strategies
during play with their toddlers with language disorder.
Importantly, these researchers adapted the intervention to
align with the linguistic and cultural backgrounds of
Latinx families prior to delivery. In both studies, children
showed gains in their productive vocabulary. The mothers
who participated in Peredo et al. also improved their use
of language facilitation strategies (e.g., expansion), which
generalized to untrained activities and were maintained
1 month postintervention. Moreover, the mothers in Ijalba
and Peredo et al. expressed satisfaction with the interven-
tions. Hence, emerging evidence suggests that PI-NLIs
may be valid and effective for supporting Latinx families,
particularly when participants’ language and culture are
considered in the design. However, the cultural, linguistic,
and contextual appropriateness of these interventions
warrants further investigation.
Sociocultural Perspectives on PI-NLIs
Language development is strongly influenced by chil-
dren’s sociocultural contexts of learning (Rogoff, 2003;
Schieffelin & Ochs, 1986; Vygotsky, 1978), which includes
the culturally informed beliefs, values, and practices of
their parents. Long-standing sociocultural norms inform
parents’ views and approaches toward interactions w ith
their young children and the kinds of supports provided at
home for early language development (Cycyk & Hammer,
in press; Hammer et al., 2007; Rodriguez & Olswang, 2003;
Rogoff et al., 1993; Schieffelin & Ochs, 1986). Similarly,
sociocultural backgrounds influence parental perspectives
on the causes and remedies for language disorders (García

et al., 2000; Rodriguez & Olswang, 2003). As such, lan-
guage interventions that match parents’ beliefs, values, and
practices may be more successful than those that do not,
leading to greater family satisfaction, participation, and out-
comes (Bailey et al., 1999; García Coll et al., 2002; Griner
& Smith, 2006; Larson et al., 2020). Thus, an awareness of
the underlying cultural orientations that inform parenting
is essential to consider the match between PI-NLIs and the
sociocultural backgrounds of Latinx families.
The well-known continuum of cultural orientation
from individualism (or independence) to collectivism (or
interdependence) is particularly relevant to parenting and
child development (e.g., Greenfield & Cocking, 1994;
Greenfield et al., 2006; Lynch & Hanson, 2004). Simply,
1–1259 • August 2020
Dow
individualism orients toward individual autonomy and
personal success, whereas collectivism orients toward inter -
dependence and group success. Extended to parenting, in-
dividualistic cultures tend to prioritize support for child
independence and individuality, whereas collectivist cul-
tures tend to emphasize the child’s responsibility to and
compliance with the group. All cultures exhibit elements of
individualism and collectivism, and individuals who affili -
ate with particular cultures also vary dynamically along
this continuum (e.g., Tamis-LeMonda et al., 2008). Yet,
the dominant culture of the United States (as linked to
Anglo-European ancestry) is characterized as highly indi-
vidualistic, whereas countries in Latin America and Latinx

immigrant communities in the United States are described
as collectivist (e.g., Caldera et al., 2015; Greenfield &
Cocking, 1994; Hofstede, 2001; Lynch & Hanson, 2004).
Importantly, most PI-NLIs have been developed in societies
dominated by individualism (i.e., United States, Australia;
Hofstede, 2001). Accordingly, PI-NLIs are largely informed
by individualistic values for child development that may
contrast with the collectivist values held by some Latinx
communities.
Traditionally, PI-NLIs advocate for parents to value
child initiation and leadership in interactions, to support
balanced turn-taking, and to ask questions and provide
frequent responses that promote child verbal expression
during dyadic parent–child interactions. As reviewed in
detail by van Kleeck (1994) and supported by the work of
Greenfield et al. (2006), these behaviors are well suited to
fostering child independence in individualistic families
where parents are the primary caregivers and verbally as-
sertive, expressive children are celebrated as equal commu-
nication partners. Families oriented toward collectivism
may not find such strategies compatible with their child-
rearing goals. Instead, maintaining adult authority in inter-
actions with children and guiding children to become com-
pliant, respectful, deferent, and competent in multiparty
interactions with several caregivers may be preferred. As
such, using directives and supporting child comprehension
may be favored over asking questions and fostering child
expression. Indeed, when Guiberson and Ferris (2019b)
observed Latinx caregivers interacting with their 2-year-old
children, the majority of caregivers used an interdependent
(i.e., collectivist) interactional style that endorsed adult
direction over child independence. Moreover, PI-NLIs may
promote school-related activities, such as sharing books
with young children or teaching pre-academic concepts
(e.g., Ijalba, 2015). Collectivist families who prioritize child

social behavior may place less emphasis on these tasks
than individualistic families who favor academic knowl-
edge (Greenfield et al., 2006; Reese & Gallimore, 2000).
However, these examples represent the extremes of the
individualism–collectivism continuum as applied to PI-NLIs;
as no culture is homogeneous, intracultural variation is
expected.
Because the Latinx population is highly diverse,
parental views on PI-NLIs are likely to represent this di-
versity. While Latinx parents of young children generally
Library, Acq Div o
report a stronger affiliation with collectivism, collectivist
and individualistic values have been noted among groups
of Latinx parents (e.g., Grau et al., 2015; Rodriguez &
Olswang, 2003). Moreover, individual parents may express
both orientations in their parenting (Guiberson & Ferris,
2019b; Hammer et al., 2007; Rodriguez & Olswang, 2003;
Tamis-LeMonda et al., 2008). Guiberson and Ferris (2019b),
for example, found that some Latinx caregivers who ad-
hered to independent or interdependent interactional styles
used behaviors with their young children that represented
the opposing cultural orientation. This variation has been
explained, in some cases, by parents’ affiliation with the
dominant individualism of the United States (as represented
by their acculturation, generational status, English proficiency,
and/or length of residence), education level, and socioeco-
nomic status (Grau et al., 2015; Rodriguez & Olswang, 2003;
Suizzo et al., 2019; Tamis-LeMonda et al., 2008). The con-
text and child’s stage of development also provoke shifts
in cultural orientation (Tamis-LeMonda et al., 2008), sug-
gesting that parents’ experiences with the individualistic
values endorsed in U.S. early childhood education (ECE)
and early intervention settings may also influence perspec-
tives on PI-NLIs. Therefore, instead of relying on the socio-

cultural orientation traditionally ascribed to Latinx parents
to determine the validity of PI-NLIs, parents of diverse
Latinx identities should be directly consulted for their views.
Parent Perspectives for Exploring Cultural
Validity of Existing Interventions
The process of exploring the perspectives of potential
intervention consumers is referred to as “social validity,”
widely considered critical for ensuring that interventions
are acceptable to stakeholders and can be effectively imple-
mented (Wolf, 1978). This process has also been referred
to as “cultural validity” or “ecological validity” (Foster &
Mash, 1999) to encompass cultural, linguistic, and contex-
tual fit. Social validity can be investigated across three
dimensions (Kazdin, 1977; Wolf, 1978), including the sig-
nificance of the goals of the intervention, the acceptability
of the procedures of the intervention (including approaches
and strategies), and the importance of the outcomes of the
intervention. Prior research has found that Latinx parents
of young children with and without language disorders
value language as a crucial developmental goal (Cycyk &
Hammer, in press; Méndez Pérez, 2000) and are pleased
with the outcomes of language interventions (Ijalba, 2015;
Peredo et al., 2018). Thus, this study explores the social
validity of common procedures of PI-NLIs. In other words,
this study addresses “treatment acceptability,” as defined
by Kazdin (1981) as the “judgments of lay persons, clients,
and others of whether the procedures proposed for a treat-
ment are appropriate, fair, and reasonable for the problem
or client” (p. 493). As parents are crucial stakeholders in
PI-NLIs, their judgments on treatment acceptability are
particularly important. Improved child language outcomes
have been found when parents perceive PI-NLI strategies
as socially valid (Dunst et al., 2016).
Cycyk & Huerta: Validity of PI-NLIs for Latinx Parents 1243

Dow
In-depth descriptions of the naturalistic contexts for
early language learning valued by some families from
Latinx backgrounds are currently available (e.g., Cycyk &
Hammer, in press). Earlier work has also hypothesized
how parents from Latinx backgrounds may perceive cer-
tain naturalistic early language intervention strategies
(Cycyk & Iglesias, 2015; van Kleeck, 1994). These authors
have suggested cultural, linguistic, and contextual adapta-
tions to match families’ natural approaches to early lan-
guage learning in order to improve the acceptability of
such interventions. However, few researchers have system-
atically asked parents for their thoughts on discrete and
specific intervention procedures commonly utilized in
PI-NLIs. Instead, small numbers of Latinx parents of chil-
dren receiving early language interventions have responded
to general queries on how they perceived the intervention
and its procedures as a whole (Ijalba, 2015; Kummerer &
Lopez-Reyna, 2009; Kummerer et al., 2007; Peredo et al.,
2018). Moreover, these parents provided their feedback
while children received the interventions or after the inter -
ventions were completed. Asking parents to react to proce-
dures prior to intervention delivery helps to develop precise
adaptations ahead of time that may enhance the social
validity of the intervention (Strain et al., 2012).
The procedures of PI-NLIs to be appraised for accept-
ability in the current study emerge from common charac-
teristics of existing PI-NLIs, as revealed in research reviews
by Akamoglu and Meadan (2018), Barton and Fettig

(2013), Law et al. (2004), and Te Kaat-van den Os et al.
(2017), as well as meta-analyses by Heidlage et al. (2020)
and Roberts and Kaiser (2011). These procedures can be
categorized by the most recurrent intervention implemen-
ters, settings, activities, language facilitation strategies, and
language(s) of intervention. See Table 1 for detailed defini -
tions. Mothers are overwhelmingly selected as the parent
who implements the strategies. Most often, the setting is
children’s homes. The activities that tend to be targeted are
parent–child play and shared book reading, regardless of
whether these activities are routine for the family. Frequent
language-facilitating strategies include following the child’s
lead, praising the child for communication attempts, imi-
tating the child’s communication attempts, expanding the
child’s communication attempts, ensuring that parent–child
conversational turns are balanced, linguistically mappi ng
the child’s activities, asking open-ended questions, increas-
ing the general quantity of talk, arranging the environmen-
tal (i.e., placing materials in view but out of reach, limiting
television), and teaching pre-academic concepts alongside
language facilitation. In addition, the language of interven-
tion (Spanish and/or English) is a key consideration for
children from Latinx homes. Many Latinx children are ex-
posed to Spanish while learning English (Federal Interagency
Forum on Child and Family Statistics, 2017). Because few
studies on PI-NLIs have included families who speak lan-
guages other than English (Akamoglu & Meadan, 2018;
Guiberson & Ferris, 2019a), PI-NLIs have mostly been
delivered in English. Yet, support for both languages in
early interventions for children exposed to Spanish and
1244 American Journal of Speech-Language Pathology • Vol. 29
• 124
Library, Acq Div o
English is considered best practice (Guiberson & Ferris,

2019a).
Purpose of the Study
In order to provide early language interventions that
are responsive to the sociocultural backgrounds of children
from Latinx- and Spanish-speaking homes, the social valid-
ity of existing PI-NLIs for this population must be exam-
ined. This exploratory study represents a pioneering step
toward meeting this need by exploring the perspectives of a
modest number of parents, many of whom were mothers
from Mexican backgrounds. First, we asked, which com-
mon PI-NLI procedures do parents perceive as acceptable?
Second, we asked, what are the reasons that parents view
common PI-NLI procedures as acceptable or not? In some
cases, this question was also asked about possible alterna-
tives to existing PI-NLI procedures as informed by prior
literature (Cycyk & Hammer, in press; Cycyk & Iglesias,
2015; van Kleeck, 1994). As a starting point, parents whose
children did not have identified language disorders were
included to investigate broad sociocultural viewpoints that
had not been influenced by the presence of child disability
or the families’ prior receipt of early intervention services.
The findings of this study will introduce SLPs to the wide
range of perspectives Latinx parents may hold toward
early language intervention procedures and highlight the
importance of including families in intervention planning.
With this information, SLPs may be better prepared to
collaborate with families to identify relevant cultural, lin-
guistic, and contextual adaptations that meet professional
mandates for early intervention (ASHA, 2008; DEC, 2014).
Moreover, this study may serve as a catalyst for future
research that seeks to develop socially valid PI-NLIs that
align with the sociocultural backgrounds of families who
are Latinx. Increasing the social validity of PI-NLIs may
ultimately lead to benefits in the effectiveness of such inter -
ventions (Dunst et al., 2016). The University of Oregon’s

Institutional Review Board approved this study.
Method
Participants
Thirty-seven parents who had at least one child un-
der the age of 6 years without parental concerns for their
communication development participated. Refer to Table 2
for parents’ background information. The parents were
recruited from four ECE centers in the Pacific Northwest
and northeastern United States. Two of these centers
provided dual language education models, whereas two
instructed in English only. Staff members of the ECE cen-
ters approached parents with information about the study
and enrolled those who were eligible. Most participants
were mothers (n = 34). Three fathers also participated. The
parents were 32.3 years of age on average (SD = 5.9 years).
Most caregivers (n = 26, 70.3%) identified as Mexican,
whereas the remainder identified as Guatemalan (n = 5),
1–1259 • August 2020
Table 1. Overview of common procedures of parent-
implemented naturalistic language interventions (PI-NLIs).
Intervention component Common procedure Definition
Intervention implementer Mothers are trained to implement
PI-NLIs
The caregiver who is taught and trained to implement language
facilitation strategies

Intervention setting Intervention takes place in the home The
setting in which the intervention is delivered
Intervention activities Language facilitation encouraged
during parent–child play and
shared book reading
The activities within which language facilitation strategies are
taught to caregivers and/or targeted with children
Language facilitation
strategies
Following the child’s lead Allowing the child’s interest to
determine material and activity
selection and following this interest to build communication
opportunities
Praising the child for communication Reacting to the child’s
communication attempts positively,
often with a specific comment and smile
Imitating the child’s communication Repeating verbatim the
child’s preceding vocalization or
verbalization
Expanding the child’s communication Adding a single infected
word to the child’s preceding nonverbal
or verbal communication attempt
Balancing parent–child conversational
turns
Matching the number of adult communication turns to the
child’s
number of communication turns

Linguistically mapping the child’s
activities
Providing the child with a linguistic model that reflects the
meaning of the child’s previous communication attempt
Asking open-ended questions Asking wh-questions that prompt
the child to communicate in a
more elaborated form (e.g., “what happened?”)
Increasing the quantity of talk Increasing the amount of
linguistic input provided to the child
(e.g., number of words, utterances)
Arranging the environment (e.g.,
limiting television, materials in
view but out of reach)
Organizing and managing situations that increase the likelihood
that the child will communicate, such as placing a desired
item out of reach but in view of the child
Teaching pre-academic concepts Practicing or explicitly
teaching counting, shapes, letters, letter
sounds, colors, and other pre-academic concepts
Language of intervention PI-NLIs delivered predominantly
in English*
The language or language(s) in which language facilitation
strategies are delivered to the child
Note. Definitions adapted from McCauley and Fey (2006) and
Paul et al. (2018).

*Few PI-NLIs have been delivered to speakers of languages
other than English. Ijalba (2015) and Peredo et al. (2018)
delivered PI-NLIs in
Spanish.
Dow
Puerto Rican (n = 2), Dominican (n = 1), Salvadorian
(n = 1), Argentinean (n =1), or as more than one Latinx
ethnicity (n = 1). The majority of parents (94%) were
immigrants to the United States. They had lived in the
United States for an average of 14.6 years (SD = 6.3, range:
7–38 years). Most parents (43%) had some schooling but
no high school diploma. Forty percent had a high school
diploma, and 14% had a bachelor’s degree. All parents
spoke Spanish at home. Parents reported that an aver-
age of 3.2 children lived in their homes. Of the children
younger than the age of 6 years, the children averaged
2.2 years of age. Most parents (96%) reported an annual
family income that was less than $40,000. A $100 gift
card and a meal during the focus group were provided for
participating.
Procedure
Four focus groups were completed, ranging from 60
to 90 min in length. Between six and 11 parents partici-
pated in each focus group. Each parent attended one focus
group in their corresponding ECE center and stayed for its
entirety, whereas their children were cared for in a sepa-
rate classroom. The focus groups were led in Spanish by
Library, Acq Div o
the first author who identifies as White of European ances-
try. The second author, who identifies as Latina, was also
present for two of the focus groups. Both authors are nation-
ally certified SLPs and speak Spanish.

First, the parents completed the informed consent
process. Then, the parents provided basic demographic in-
formation on a written questionnaire available in Spanish
and English. Questions were taken from the Center for
Early Care and Education Research: Dual Language Learner
Parent Questionnaire (Hammer et al., 2015), which was
originally validated with 317 Latinx parents of young chil -
dren. Support in the form of reading the questions and
potential responses aloud was provided for two parents with
low literacy levels.
Next, the moderator explained the focus group pro-
cedures and purpose. A standardized script was then used to
ask for parents’ perspectives on 14 procedures common to
PI-NLIs specific to intervention implementers, settings,
activities, language facilitation strategies, and language(s)
of intervention. As a reminder, these procedures were
determined from information provided by reviews and meta-
analyses that revealed the …
Dow
AJSLP
Research Article
aCommunicat
bCommunicat
University, N
cSchool of Nu
Philadelphia,
dDepartment
Mexico, Albu
ePsychologica
Tampa
Corresponden

Editor-in-Chi
Editor: Li She
Received Mar
Revision rece
Accepted Sep
https://doi.org
Ameri174
nloaded from:
Effects of Home Language, Oral Language
Skills, and Cross-Linguistic Phonological
Abilities on Whole-Word Proximity in
Spanish-English–Speaking Children
Shelley E. Scarpino,a Carol Scheffner Hammer,b Brian
Goldstein,c
Barbara L. Rodriguez,d and Lisa M. Lopeze
Purpose: This study examined language use and language
ability factors that predict phonological whole-word proximity
in young Spanish-English–speaking children.
Method: Participants were 199 Latino children aged 3;0–
6;6 (years;months) and their mothers. Children’s speech sound
production in English and Spanish was assessed using the
Bilingual Phonological Assessment (Miccio & Hammer, 2006).
Vocabulary and story retell abilities were assessed using the
Woodcock-Muñoz Language Survey–Revised (Woodcock,
Muñoz-Sandoval, Ruef, & Alvarado, 2005), and information
regarding the children’s exposure to and use of English
and Spanish was collected by means of a parent survey.
Hierarchical regression analyses were used to determine the

degree to which exposure to and use of each language in the
home, oral language abilities, and phonological proficiency
ion Sciences and Disorders, Bloomsburg University, PA
ion Sciences and Disorders, Teachers College, Columbia
ew York, NY
rsing and Health Sciences, La Salle University,
PA
of Speech & Hearing Sciences, The University of New
querque
l and Social Foundations, University of South Florida,
ce to Shelley E. Scarpino: [email protected]
ef: Julie Barkmeier-Kraemer
ng
ch 12, 2018
ived August 6, 2018
tember 13, 2018
/10.1044/2018_AJSLP-18-0050
can Journal of Speech-Language Pathology • Vol. 28 • 174–187
• Febru
https://pubs.asha.org CUNY, Lehman College - Library, Acq
Div o
as measured by the proportion of whole-word proximity
(PWP; Ingram, 2002) in the other language were able to
predict the PWP scores in English and Spanish.
Results: A large portion of the variance in English and
Spanish PWP scores (R2 = .66 and .51, respectively) was
predicted by the language children use when communicating
with their mothers, children’s vocabulary scores, and
children’s PWP scores in the other language.
Conclusion: Language use, vocabulary, and phonological
whole-word proximity in the other language are significant
factors in predicting bilingual children’s whole-word proximity

in English and Spanish. Children’s phonological abilities in
one language are highly predictive of those same abilities in
the other, suggesting underlying shared phonological skills
across languages.
The Latino population continues to be one of thefastest growing
in the United States. It is predictedthat by the year 2050, nearly
39% of children under
the age of 5 years will come from homes where Spanish
is spoken (U.S. Census Bureau, 2012). A growing body
of research has shown that phonological development in
Spanish-English (S-E) dual language learners (DLLs) differs
from that of their monolingual peers in rate of acquisition,
segmental accuracy, and use of phonological patterns
(Dodd, So, & Wei, 1996; Fabiano-Smith & Goldstein, 2010;
C. Gildersleeve-Neumann & Davis, 1998; C. E. Gildersleeve-
Neumann, Kester, Davis, & Peña, 2008; B. Goldstein &
Washington, 2001). However, specific factors that affect
DLLs’ phonological development in each language are not
well understood.
The importance of understanding phonological
development in a given population cannot be overstated,
given the pivotal role of phonology in overall language and
literacy acquisition. Research has shown that children’s
early lexical and phonological abilities develop in tandem
(e.g., McCune & Vihman, 2001). Furthermore, phonological
development is essential for expanding the complexity of chil -
dren’s grammar through the acquisition of morphosyntactic
structures. Additionally, children with poor phonological
skills have been shown to be at risk for other language-
related deficits along with deficits in early reading skills
Disclosure: The authors have declared that no competing
interests existed at the time
of publication.
ary 2019 • Copyright © 2019 American Speech-Language-

Hearing Association
https://doi.org/10.1044/2018_AJSLP-18-0050
Dow
(Bird, Bishop, & Freeman, 1995; Nathan, Stackhouse,
Goulandris, & Snowling, 2004). Because phonological
skills are so critical to overall language and early literacy
abilities, a better understanding of factors that contribute
to phonological proficiency in S-E DLLs is needed.
Children’s exposure to and use of each language
measured in terms of timing of second language acquisi-
tion, length of language exposure, language dominance,
and overall language abilities in each language have
been shown to affect phonological acquisition in DLLs
(Gildersleeve-Neumann et al., 2008; Goldstein, Bunta,
Lange, Rodriguez, & Burrows, 2010; Goldstein, Fabiano,
& Washington, 2005). However, because all of these fac-
tors have not been investigated collectively within a single
study, the relative importance of each factor, while control -
ling for the influence of the others, is not well understood.
Also, while evidence has shown that children’s phonologi-
cal skills are similar in their two languages (e.g., Fabiano-
Smith & Goldstein, 2010), the degree to which phonological
proficiency in one language predicts it in the other has not
been directly investigated. The current study investigates
factors of language exposure and use, related to children’s
interactions with their mothers, and oral language skills on
S-E–speaking children’s phonological proficiency in each
language. It also extends previous research by investigating
the role of cross-language phonological proficiency on DLLs’

Spanish and English single-word productions.
Language Input and Usage
Usage-based models of language acquisition, such as
the Unified Competition Model (MacWhinney, 2005), aid
in conceptualizing the development of the two phonological
systems of DLLs within the framework of language input
and use. According to this model, the frequency and nature
of linguistic cues in the input (e.g., children’s exposure to
speech sounds in Spanish and English) determine which
phonemes eventually become part of their phonological
system. The amount of input received in each language can
be conceptualized as the length of time children have been
exposed to a language (e.g., the number of years) and/or
the concurrent amount of input they receive in each language
(e.g., all Spanish; all English; varying amounts of each).
Language input and language use have been empir-
ically shown to affect bilingual children’s oral language
abilities; however, the effects of these variables on lan-
guage outcomes seem to depend on how they are defined
and estimated. For example, estimates of cumulative expo-
sure, calculated by determining when the child was first
exposed to a language, do not correlate as well with oral
language or phonological skills as do estimates of concur-
rent daily language use and exposure (Bedore et al., 2012;
Bohman, Bedore, Peña, Mendez-Perez, & Gillam, 2010;
Cooperson, Bedore, & Peña, 2013; Gutierrez-Clellen &
Kreiter, 2003; Ruiz-Felter, Cooperson, Bedore, & Peña,
2016). Cooperson et al. (2013) found that percent of English
input–output predicted 2.6% of the unique variance in
English phonological accuracy, whereas age of first exposure
Library, Acq Div o
was not significantly related. Goldstein et al. (2010) found

that length of time since first exposure to English had no
effect on consonant or vowel accuracy in young DLLs,
whereas Gildersleeve-Neumann et al. (2008) found that ex-
posure to English, calculated as mean daily input–output,
did have a significant effect on phonological outcomes,
namely, those children with the least exposure to English
on a daily basis had the lowest English speech sound
accuracy.
Some studies have also found language input and use
to be related to one language in S-E DLLs, but not to the
other. For example, Gutiérrez-Clellen and Kreiter (2003)
found language experience to be related to Spanish, but not
to English outcomes. Contrastively, Cooperson et al. (2013)
found that exposure to English predicted a small but sig-
nificant variance in English phonological skills; however,
neither age of first exposure nor percent of combined daily
input–output significantly correlated with Spanish phono-
logical accuracy. In these studies, children’s reported lan-
guage input was averaged with their reported use of language
(output) to obtain an input–output measure, thereby making
it impossible to tease out the unique contribution of input,
as opposed to output, on phonological proficiency.
Some of the inconsistencies across study findings
regarding the relation between language input–use and
phonological accuracy could be due to the different mea-
sures used by researchers to quantify this very diverse factor.
Also, because input and output measures were not evaluated
separately in most studies, it is not possible to determine
the unique contributions of input and output to language
and phonological outcomes in DLLs. Finally, the disparate
findings of the effects of language input and use on phono-
logical accuracy in prior studies could be due, in part, to
small sample sizes (Gildersleeve-Neumann et al., 2008;
Goldstein et al., 2005). In the present study of nearly 200

participants, children’s current language input and output
will be measured using a parent report of languages used
during mother-to-child interactions on a 5-point scale. As
a measure of children’s cumulative language experience,
length of expressive use of language, in addition to length
of exposure, will be derived from the age at which the child
began saying words in each language. The effects of these
language experience factors will be evaluated simultaneously
along with additional factors believed to affect phonological
accuracy (i.e., cross-linguistic phonological skills and oral
language skills), within a rather large pool of participants,
thus extending the findings of previous studies.
Cross-Linguistic Phonological Skills
When a DLL’s two languages have similar, frequently
occurring phones and phonotactics, the Unified Competition
Model predicts that the activation cues for these phono-
tactics and phones will be strengthened in both languages.
This strengthening occurs because the DLL likely assumes
that the words of one language are composed of strings of
phones of the other (MacWhinney, 2005). Thus, phones
and phonotactic patterns that occur in both languages will
Scarpino et al.: Whole-Word Proximity in Spanish-English 175
https://pubs.asha.org/pubs/rights_and_permissio ns
Dow
be readily transferred, resulting in a more accurate produc-
tion of each language than would be expected if children
were “starting from scratch” to develop phonological skills
in each language. This process is known as forward transfer
(Gorman & Gillam, 2003). As an emergentist, usage-based

1. consider the lewis two sector model. what are the 2 main assump

1. consider the lewis two sector model. what are the 2 main assump

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to 1. consider the lewis two sector model. what are the 2 main assump

Similar to 1. consider the lewis two sector model. what are the 2 main assump (20)

More from SUKHI5

More from SUKHI5 (20)

Recently uploaded

Recently uploaded (20)

1. consider the lewis two sector model. what are the 2 main assump