Benzodiazepine exposure and functional status in older people

OBJECTIVE: To determine the association between benzodiazepine exposure and functional status in older patients. DESIGN: A nonexperimental, observational study design. SETTING: Kaiser Permanente, Northwest Division, a health maintenance organization (HMO) providing prepaid, comprehensive inpatient and outpatient care for more than 410,000 persons. PATIENTS: Patients were the 4192 Social HMO Project members 65 years of age and older, enrolled for 1 full year, who returned their annual health status survey during 1990. MEASUREMENTS: Functional status was measured using self-reported activities of daily living and instrumental activities of daily living. Predictor variables were self-reported medical conditions and benzodiazepine exposure during the previous 12 months. RESULTS: Age, gender, and living status were associated with functional status. Severe memory loss, stroke, Parkinson's disease, circulation problems, lung problems, hip fracture, urinary problems, arthritis, heart trouble, diabetes, stomach/bowel problems, and cancer were associated independently with functional status. Persons exposed to a benzodiazepine scored lower on the functional status measure. Benzodiazepine exposure added significantly to the prediction of functional status after controlling for patients' sociodemographic characteristics and medical conditions. CONCLUSIONS: Age and medical conditions were the most significant predictors of functional status. Benzodiazepine exposure was associated with functional status to the same extent as several chronic medical conditions. When prescribing benzodiazepines for older people, caution should be taken to minimize the possibility of iatrogenic-functional limitations.