THE CLINICIAN INTERVIEW-BASED IMPRESSION (CIBI) - A CLINICIAN GLOBAL CHANGE RATING-SCALE IN ALZHEIMERS-DISEASE

Global assessments are Food and Drug Administration-required primary o utcome measures in trials of putative antidementia drugs. Global ratin gs are intended to provide an index of clinical importance of change t hat cannot be obtained from quantitative assessment measures such as m ental status examinations. We examined the performance of a global ass essment of change instrument, the Clinician Interview-Based Impression (CIBI), in the placebo group of a 30-week, randomized, double-blind c linical trial of tacrine in patients with Alzheimer's disease. Initial ly there were 184 placebo patients, of whom 125 completed the 30-week study. Descriptive statistics, correlations with changes on other asse ssment instruments, and test-retest reliability were determined for th e CIBI. At week 30, clinicians rated more than 40% of patients on the CIBI as unchanged. The CIBI ratings were weakly but significantly corr elated, in the expected direction, with change scores on the quantitat ive cognitive assessments. The CIBI was modestly reliable on test-rete st at weeks 22 and 24 but less reliable compared with other quantitati ve outcome measures. Modifications of the CIBI that might improve its reliability and acceptance include (1) no restrictions on the form of the bedside mental status assessment, (2) inclusion of caregiver input , and (3) better definition of ratings on the global scale. Global ins truments, if properly constructed, can provide an index of clinically important change for the assessment of dementia patients.