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Review
. 2013:9:1359-70.
doi: 10.2147/NDT.S49520. Epub 2013 Sep 19.

Confusion assessment method: a systematic review and meta-analysis of diagnostic accuracy

Qiyun Shi  1 , Laura Warren, Gustavo Saposnik, Joy C Macdermid
Affiliations
Review

Confusion assessment method: a systematic review and meta-analysis of diagnostic accuracy

Qiyun Shi et al. Neuropsychiatr Dis Treat. 2013.

Abstract

Background: Delirium is common in the early stages of hospitalization for a variety of acute and chronic diseases.

Objectives: To evaluate the diagnostic accuracy of two delirium screening tools, the Confusion Assessment Method (CAM) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU).

Methods: We searched MEDLINE, EMBASE, and PsychInfo for relevant articles published in English up to March 2013. We compared two screening tools to Diagnostic and Statistical Manual of Mental Disorders IV criteria. Two reviewers independently assessed studies to determine their eligibility, validity, and quality. Sensitivity and specificity were calculated using a bivariate model.

Results: Twenty-two studies (n = 2,442 patients) met the inclusion criteria. All studies demonstrated that these two scales can be administered within ten minutes, by trained clinical or research staff. The pooled sensitivities and specificity for CAM were 82% (95% confidence interval [CI]: 69%-91%) and 99% (95% CI: 87%-100%), and 81% (95% CI: 57%-93%) and 98% (95% CI: 86%-100%) for CAM-ICU, respectively.

Conclusion: Both CAM and CAM-ICU are validated instruments for the diagnosis of delirium in a variety of medical settings. However, CAM and CAM-ICU both present higher specificity than sensitivity. Therefore, the use of these tools should not replace clinical judgment.

Keywords: confusion assessment method; delirium; diagnostic accuracy; meta-analysis; systematic review.

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Figures

Figure 1
Figure 1
Result of literature search. Abbreviation: DSM-IV, Diagnostic and Statistical Manual of Mental Disorders IV.
Figure 2
Figure 2
Bivariate estimate of sensitivity and specificity. Notes: Bivariate summary estimates of sensitivity and specificity for delirium screening test with 95% confidence and prediction ellipses. Upper left dots represent sensitivity and specificity of the Confusion Assessment Method and the Confusion Assessment Method for the intensive Care Unit. Smaller ellipses represent 95% confidence interval of sensitivity and specificity. Larger ellipses represent 95% confidence interval of prediction sensitivity and specificity. Red color represents the Confusion Assessment Method for the intensive Care Unit and the black color represents the Confusion Assessment Method. Abbreviations: CAM, Confusion Assessment Method; CAM-ICU, Confusion Assessment Method for the intensive Care Unit.
Figure 3
Figure 3
Summary receiver operating characteristic curve of delirium screen scales.
Figure 4
Figure 4
Funnel plot of delirium screen scales. Abbreviations: TP, true positive; FP, false positive; FN, false negative; TN, true negative.
See this image and copyright information in PMC

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