The document summarizes 15 research articles that evaluated the accuracy of the Confusion Assessment Method for the ICU (CAM-ICU) in identifying delirium in adult ICU patients compared to practitioner judgment. The majority of studies were quasi-experimental and found that the CAM-ICU more accurately identified delirium than practitioner judgment alone. However, the CAM-ICU had lower sensitivity than specificity, so it could potentially under-identify delirium. The studies concluded that while the CAM-ICU is currently the most accurate tool, it should be used along with practitioner judgment until a screening tool with higher sensitivity is developed.

1. 15 Research Articles
15 Quantitative
Articles
12 Quasi-
Experimental
Studies
2 Level II, Quality A
9 Level II, Quality B
1 Level II, Quality C
2 Systematic
Reviews
1 Level IV, Quality A
1 Level IV, Quality B
1 Retrospective non-
experimental study 1 Level III, Quality B
Use
of
the
Confusion
Assessment
Method
to
Assess
Delirium
in
the
ICU
Setting
Kristen Emelio, Christina Halsey, Priscilla Nhi Le, Safa Soliman
Background ConclusionLiterature Review Methods
Clinical Question & PICO
Definitions
Recommendation
In adult ICU patients, does the use of the Confusion
Assessment Method (CAM-ICU) increase accurate
identification of ICU delirium compared to practitioner
judgment?
P: Adult ICU patients
I: Confusion Assessment Method for the ICU
C: Practitioner judgment
O: Accurate identification of ICU delirium
v Delirium occurs in up to 80% of patients in the ICU
(Gusmao-Flores et al., 2011), and goes undetected in up
to 72% when routine monitoring is not in place.
(Guenther et al., 2012).
v Delirium is a predictor of increased length of stay,
mortality, and treatment costs in critical care patients.
v The current standard diagnostic criteria is the
Diagnostic and Statistical Manual of Mental Disorders
(DSM-5). However, this diagnostic tool cannot be easily
applied to daily bedside practice. (Shi, Warren, &
MacDermid, 2013).
v The Confusion Assessment Method (CAM-ICU) for the
ICU is the most widely used screening tool for ICU
delirium. However, many ICUs do not utilize objective
tools and rely on practitioner judgment for delirium
identification. (Shi, Warren, & MacDermind, 2013).
v Delirium: a disturbance of consciousness
characterized by acute onset and a fluctuating course of
inattention accompanied by either a change in
cognition or perceptual disturbance so that a patient’s
ability to receive, process, store, and recall information
is impaired. (Lemiengre et al., 2006).
v CAM-ICU: an assessment tool to identify ICU delirium
v Practitioner Judgment: the unstructured and
subjective assessment of delirium based on knowledge
and clinical experience (also referred to as clinical
judgment)
Databases: PubMed, CINAHL, and Google Scholar
Search Terms: Confusion Assessment Method, CAM-ICU, CAM, ICU, Delirium, Practitioner Judgment
Author(s) and
year
Level of
Evidence
Type of study Methods Results
Guenther et
al. (2012)
Level II
Quality B.
Quasi-
experimental
observational
cohort study
160 adult ICU patients were assessed
for delirium by trained medical
students who used CAM-ICU and
bedside ICU nurses who used clinical
judgment in paired observations.
v The bedside nurses identified 29.4% of participants as delirious,
and the medical students using the CAM-ICU identified 26.2% of
these patients as delirious.
v Nurses’ subjective assessment potentially overestimated
delirium and did not identify delirium in a worrisome number of
patients who were identified as delirious by the CAM-ICU.
Mistarz,
Eliott,
Whitfield, &
Ernest (2011)
Level II
Quality B.
Quasi-
experimental
observational
study
35 adult ICU patients were assessed
for delirium by bedside nurses using
clinical judgment. This assessment
was then compared to a separate
assessment using the CAM-ICU
performed by a trained nurse.
v Delirium was identified by bedside nurses in 3/5 (27%) of the
patients who had a positive CAM-ICU. The absence of delirium
was identified by bedside nurses in 22/30 (92%) the patients who
had negative CAM-ICU.
v Researchers concluded that the detection of delirium through
subjective clinical judgment is unreliable in the ICU.
Spronk,
Riekerk,
Hofhuis, &
Rommes
(2009)
Level II
Quality B.
Quasi-
experimental
observational
study
Intensivists and ICU nurses assessed
46 adult ICU patients for delirium
using clinical judgment. This
assessment was then compared to
their CAM-ICU score.
v 50% of the patients were identified as delirious according to the
CAM-ICU.
v Compared to this, delirium was poorly recognized by physicians
(28.0% sensitivity and 100% specificity) and by ICU nurses
(34.8% sensitivity and 98.3% specificity).
v Researchers concluded that ICU delirium is severely under-
diagnosed by intensivists and ICU nurses using subjective
judgment.
van Eijk et al.
(2009)
Level II
Quality B.
Quasi-
experimental
prospective
cohort study
126 adult ICU patients were assessed
for delirium by nurses using the
CAM-ICU or Intensive Care
Delirium Screening Checklist
(ICDSC), as well as the ICU
physicians’ clinical judgment. A
reference rater used DSM-IV
criteria, which served as the gold
standard to diagnose delirium.
v According to reference rater evaluation, 34% of patients were
diagnosed as delirious.
v The CAM-ICU showed superior sensitivity and negative
predictive value (64% and 83%) compared with the ICDSC (43%
and 75%).
v The physicians using clinical judgment missed almost three
quarters of all ICU delirium with a sensitivity of only 29%.
The studies collectively concluded that:
v The CAM-ICU was more accurate in
identifying ICU delirium than practitioner
judgment
v Delirium was significantly under-diagnosed
using practitioner judgment alone
v The studies agreed that CAM-ICU is a valid
and reliable tool. (Luetz et al., 2010).
v However, they collectively found the
sensitivity (47%-83%) to be lower than the
specificity (96%-98%). (Luetz et al., 2010;
Gusmao-Flores et al., 2011; Shi, Warren, &
MacDermid, 2013; van Eijk, 2011). A lower
sensitivity could have been due to a lack of
CAM-ICU user training in some studies.
v This could potentially increase the risk of
under-identifying delirium using CAM-
ICU.
Other Important Findings
Selected Articles
v Hospitals should implement the use of an
objective screening tool over subjective
clinical judgment to identify ICU delirium.
v The CAM-ICU is the most accurate tool
currently used to detect delirium. However,
superior sensitivity is necessary for a
screening tool, so CAM-ICU should not be
relied upon alone for diagnosis. (Shi, Warren,
& MacDermid, 2013).
v Because of this, CAM-ICU should be used
along with practitioner judgment until a
more accurate tool with higher sensitivity is
developed for clinical practice.
v Future studies should focus on developing an
objective tool with higher sensitivity than
CAM-ICU to detect ICU delirium.