Literacy influences asthma patients’ trust of their physician through knowledge of management. The study assessed how patient literacy impacts trust in their doctor by examining patients' understanding of inhaled corticosteroids (ICS), a key asthma medication. The study found that poorer performance on a numeracy assessment, but not a general health literacy test, was associated with less knowledge of ICS and lower trust in their doctor. Knowledge of ICS function mediated the relationship between numeracy and trust. Future research should explore how interventions can leverage these relationships to improve asthma outcomes.

1. Literacy influences asthma patients’ trust of their physician
through knowledge of management
Apter A.J., Bennett I. M., Bogen D., Garcia L.A., Sharpe T., Jackson D., Priolo C., Gonzalez R., Wang X., Ten Have T.
University of Pennsylvania, Philadelphia, PA
Introduction Results Results - continued
 Trust is a critical element of the patient-doctor relationship.1 Table 1. Characteristics of 80 Participants Table 2. Literacy, Trust, and ICSK
 We hypothesize trust may be affected by how well patient and doctor understand Age (years)* 47 13 Descriptive analysis
each other. Female 55 ANQ
 Understanding may be influenced by patient literacy. % participants with at least 2/4 53%
Race** incorrect items
 Half of the US population has only basic reading and numerical skills.2 Black/African American 52 mean* 2.3 + 1.2
 Asthma self-management requires significant literacy skills, including numerical White 15 S-TOFHLA
skills..3,4 % Inadequate health literacy 11%
Other*** 5 (score 0-16)
 Self-management depends heavily on understanding the function of inhaled
corticosteroids (ICSs), an essential medication for all but the mildest asthma. No response/declined 10 % Marginal functional health 8%
literacy (score 17-22)
 The goal of this study was to assess the impact of literacy on patients’ trust of their Ethnicity: Hispanic/Latino 9 Figure 2. Univariable
asthma physician and whether it is mediated by knowledge of ICS function. % Adequate health literacy 81% (upper) and Multivariable
Household income < $30,000 per year 53 (66%) (score 23-36)
# High school graduate 69 ( 86%) PCAS Trust (score 8- 40) 38 + 4.3 (lower) Analyses
ICS Knowledge 36 + 6
# Hospitalized for asthma in past year 21 (26%) ICSK
# Had ED visits for asthma in past year 39 (49%)
(0.43, 0.001) (0.45, <0.001)
Methods Baseline FEV1 as percent predicted* 66% 17% (0.27, 0.02)
(rho, p)
(0.31, 0.01)
 Design: Observational cross-sectional study of baseline data from a large randomized * Mean + Standard deviation. **Some subjects selected multiple options.
***American Indian/Alaskan Native, Native Hawaiian/Pacific Islander ANQ Trust
controlled intervention to improve adherence and asthma outcomes in adults with (0.28, 0.01)
moderate or severe asthma (0.18, 0.14)
 Subjects: ≥18 yrs with moderate or severe persistent asthma recruited from clinical sites  ANQ but not S-TOFHLA was positively associated
that serve low income populations Figure 1. Asthma Numeracy Questionnaire (ANQ) with ICSK. Multivariable correlation rho p
 ANQ was negatively associated with age and model of Trust
 FEV1< 80% ppd at least once in the past 3 yrs 1. Your doctor asks you to take 30 mg of prednisone every day % of subjects African American.
ANQ 0.05 0.68
for a week. The pharmacist gives you a bottle of 5 mg tablets. with correct  ICSK mediates the relationship between
 Reversibility with bronchodilator or treatment answer numeracy & trust (see above). ICSK 0.31 0.01
How many pills should you take each day?
 Prescribed an inhaled corticosteroid  In multivariable correlation analysis, adding ICSK
 80% to the model on numeracy and trust and controlling
age -0.01 0.97
 Data Collection: for age and African American, reduces the Latino -0.10 0.40
 Socio-demographics 2. If a patient has a 1% chance of developing osteoporosis or association of numeracy with trust beyond the African American 0.07 0.58
bone loss: reduction due to confounding by nonmodifiable
 Asthma severity (hospitalizations, ED visits, FEV1) demographic variables (age, race).
that means
 Asthma Numeracy Questionnaire (ANQ)4 a. Out of 1000 patients, one will develop bone loss
 Short Test of Functional Health Literacy in Adults (S-TOHFLA)6 b. Out of 100 patients, one will develop bone loss Conclusions/Discussion
 Trust Subscale of the Primary Care Assessment Survey7 c. Out of 10 patients, one will develop bone loss 46%
 Inhaled Steroid Knowledge Questionnaire (ICSK) 8,9 d. Out of 5 patients, one will develop bone loss
 Analysis:
e. The patient will develop bone loss • We found evidence that poor understanding of knowledge of ICS function,
f. The patient will never develop bone loss whether or not directly concerning numerical issues mediates this
 The literacy – trust relationships were assessed with correlations and regression
models to which an ICSK variable was added as a potential mediator along this 3. You have a peak flow meter. Your Danger or Red Zone is
association of numeracy with trust based on a reduction in partial correlation.
confounder variables. 50% of your best reading. Your best reading is 400 L/min. • Future research is warranted to determine how interventions might make
 Confounders (demographic variables) were defined to be variables that What is your Danger Zone?
conceptually impacted either trust, ICS knowledge, or literacy.
use of this relationship to improve asthma outcomes.
L/min or less 71%
4. You are told the Green Zone (the OK zone) is a reading
between 80% and 100% of your best reading. Your Worry
Zone is between 50% and 80% of your best reading. Your References
best reading is 400 L/min. When are your readings in the
Worry Zone? 1 Pearson S et al. JGIM 2000;15:509-13.
2 Kutner M, Greenberg E, et al. The Health Literacy of America’s Adults. National Center for
a. Between 300 and 400 L/min
36%
Education Statistics, US Department of Education, 2006
b. Between 200 and 320 L/min 3 Apter AJ, Paasche-Orlow MK, Remillard JT, Bennett IM, et al. J Gen Intern Med 2008;23;2117:24.
Support c.
d.
Between 200 and 300 L/min
Between 240 and 320 L/min
4 Apter AJ, Cheng J, Small D, Bennett IM et al. J Asthma 2006;43:705-10.
5 Expert Panel Report 3: guidelines for the diagnosis and management of asthma. National Heart,
e. Between 100 and 300 L/min Lung and Blood Institute 2007;NIH Publication #08-5846.
Support: HL073932, HL088469 6 Baker DW, Williams MV, Parker RM, et al. Patient Educ Couns 1999;38-33-42.
7 Safran DG et al.Med Care 1998;36:728-39.
8 Apter AJ et al. Am J Respir Crit Care Med 1998;157:1810-17.
9 Apter AJ et al. J Allergy Clin Immunol 2003;111:1219-26.