Benzodiazepine use and physical performance in community-dwelling older women.

OBJECTIVES: To determine whether benzodiazepine use in older women increased the risk of decline in physical function.
DESIGN: A four-year prospective cohort study.
SETTING: The communities of Iowa and Washington counties, Iowa. PARTICIPANTS: Eight hundred eighty-five women aged 70 and older who had completed physical performance tests in 1988 and 1992. MEASUREMENTS: Benzodiazepine use was determined during in-home interviews and classified by dose, duration, indication for use, and half-life. Physical performance tests included an assessment of standing balance, walking speed (8-foot distance), and repeated chair raises.
RESULTS: Ninety (10.2%) reported benzodiazepine use at baseline. After adjustment for baseline physical performance score and potential confounders, benzodiazepine use was associated with a greater decline in physical performance over 4 years than nonuse (beta=-1.16; standard error (SE)=0.25; P<.001). The use of higher-than-recommended dose was related to decline (beta=-2.26; SE=0.47; P<.001), and use of lower doses was not (beta=-0.53; SE=0.46; P=.246). Long-term use (>or=3 years) was related to decline (beta=-1.65; SE=0.34; P<.001), whereas recent and past use were not. Similar results were obtained when restricting the sample to those without disability at baseline.
CONCLUSION: This study provides evidence that older women who used benzodiazepines were at risk for decline in physical performance. Subgroup analyses indicated that risk was greater with use of higher-than-recommended doses or for long duration (>or=3 years). These findings highlight the importance of using benzodiazepines at the lowest effective dose for a limited duration in older women.