Long-term continuous use of benzodiazepines by older adults in Quebec: Prevalence, incidence and risk factors

OBJECTIVE: To determine the prevalence and incidence of long-term use of benzodiazepines and to assess patient-, prescriber-, and drug-related risk factors. DESIGN: Cohort study. PARTICIPANTS: 1423 community-dwelling older adults in Quebec who participated in the Canadian Study of Health and Aging (CSHA1). MEASUREMENTS: Patient characteristics were obtained from the CSHA1 database. These were linked to provincial health insurance data to ascertain benzodiazepine use and prescriber characteristics. MAIN OUTCOME MEASURE: Use of benzodiazepines for at least 135 of the first 180 days following initiation of use. RESULTS: Twelve-month prevalence of long-term continuous use, standardized by age and gender to the Quebec population, was 19.8%. Twelve-month cumulative incidence of long-term continuous use was 1.9%. Older patients were more likely to proceed to long-term continuous use. CONCLUSIONS: Risk of long-term continuous use of benzodiazepines seems to increase with age. This association was found to be independent of gender, health status, anxiety, cognitive status, benzodiazepine type, and physician characteristics.