BioPsychoSocial Assessment Tools for the Elderly - Assessment Summary Sheet

Test: Confusion Assessment Method (CAM)

Year: 1990

Domain: Psychological

Assessment Tool Category: Delirium

Variations/Translations: Both a long and short version of the CAM are available. The long version is a comprehensive assessment instrument that screens for clinical features of delirium and correlates to Diagnostic and Statistical Manual of Mental Disorders-Four (DSM-IV) criteria. The short version includes only those four features that were found to have the greatest ability to distinguish delirium from other types of cognitive impairment. There is also a CAM-ICU version for use with non-verbal mechanically ventilated patients.

Setting: Clinical and research settings

Method of Delivery: Interview

Description: The Confusion Assessment Method (CAM) was intended to provide a new standardized method to enable non-psychiatrically trained clinicians to identify delirium quickly and accurately in both clinical and research settings. The CAM includes two parts. Part one screens for overall cognitive impairment. Part two includes only those four features that were found to have the greatest ability to distinguish delirium or reversible confusion from other types of cognitive impairment.

Scoring/Interpretation: The diagnosis of delirium by CAM requires the presence of features 1 and 2 and either 3 or 4.

Feature 1: Acute Onset or Fluctuating Course

Feature 2: Inattention

Feature 3: Disorganized thinking

Feature 4: Altered Level of consciousness

Time to Administer: Less than 5 minutes

Availability: Available online for download

Software: N/A

Website: http://consultgerirn.org/uploads/File/trythis/issue13_cam.pdf

Quantitative/Qualitative: Quantitative

Validity (Quantitative): Concurrent validation with psychiatric diagnosis revealed sensitivity of 94-100% and specificity of 90-95%. The CAM significantly correlated with the Mini-Mental Status Examination, the Visual Analog Scale for Confusion and the Digit span test.

Reliability (Quantitative): Interrater reliability yielded .86 (Monette, 2001).

References:

Ely, E. Wesley, Margolin, R., Francis, J., May, L., Truman, B., Dittus, R, Speroff, T., Gautam, S., Bernard, G., & Inouye, S. (2001). Evaluation of delirium in critically ill patients: Validation of the Confusion Assessment. Method for the Intensive Care Unit (CAM-ICU). Critical Care Medicine, 29(7): 1370-1379.

Monette, J., Galbaud du Fort, G., Fung, S.H., Massoud, F., Moride, Y., Arsenault, L., & Afilalo, M. (2001). Evaluation of the confusion assessment method (CAM) as a screening tool for delirium in the emergency room. General Hospital Psychiatry, 23(1): 20-25.

Inouye, S.K. (2006). Delirium in older persons. New England Journal of Medicine, 354: 1157-65.

Inouye, S.K., Foreman, M.D., Mion, L.C., Katz, K.H., & Cooney, L.M. (2001). Nurses’ recognition of delirium and its symptoms: Comparison of nurse and researcher ratings. Archives of Internal Medicine, 161: 2467-2473.

Inouye, S., van Dyck, C., Alessi, C., Balkin, S., Siegal, A. & Horwitz, R. (1990). Clarifying confusion: The confusion assessment method. Annals of Internal Medicine, 113(12): 941-948.

Comments:

This tool closely correlates with DSM-IV criteria for delirium. There is a false positive rate of 10% and the instrument has not been widely tested as a bedside tool for nurse raters. The tool identifies the presence or absence of delirium but does not assess the severity of the condition, making it less useful to detect clinical improvement or deterioration.