Screening for delirium using family caregivers: convergent validity of the Family Confusion Assessment Method and interviewer-rated Confusion Assessment Method.

OBJECTIVES To explore agreement between the Family Confusion Assessment Method (FAM-CAM) for delirium identification and interviewer-rated CAM delirium ratings. DESIGN Exploratory analysis of agreement. SETTING Community. PARTICIPANTS Fifty-two family caregivers and 52 elderly adults with preexisting impairment according to standardized cognitive testing. MEASUREMENTS The interviewer-rating for delirium was determined by fulfillment of the CAM algorithm RESULTS The total sample included 52 paired CAM:FAM-CAM assessments completed across 52 dyads of elderly adults with preexisting cognitive impairment and family caregivers. The point prevalence of delirium was 13% (7/52). Characteristics did not differ significantly between the groups with and without delirium. The FAM-CAM questions that mapped directly to the original four-item CAM algorithm had the best overall agreement with the interviewer-rated CAM (kappa = 0.85, 95% confidence interval (CI) = 0.65-1.0), sensitivity of 88% (95% CI = 47-99%), and specificity of 98% (95% CI = 86-100%). CONCLUSION The FAM-CAM is a sensitive screening tool for detection of delirium in elderly adults with cognitive impairment using family caregivers, with relevance for research and clinical practice.