Although benzodiazepine use among older, community-dwelling persons is common, especially among women, it has been associated with negative consequences, including fall risk, depression, hip fractures, and cognitive decline. Measurement of physical function using performance-based measures is a possible way of detecting functional impairment before disability is observed. In general, performance-based measures are highly predictive of subsequent disability. Gray and colleagues prospectively studied the effect of benzodiazepine use on the change in physical performance over a four-year period in community-dwelling, older women.

Data were collected as part of the Established Populations for Epidemiologic Studies of the Elderly (EPESE) study. The sample for this analysis was 885 women 70 years and older (too few men were taking benzodiazepines to include them in the study). The authors collected data on baseline benzodiazepine use, dosage, indication, and duration of use. Physical performance measures included balance, walking speed, and time to rise from a chair five times. Statistical analysis evaluated whether participants experienced decline, improvement, or no change with benzodiazepine use.

Of the 885 women participating, 90 (10.2 percent) reported benzodiazepine use at baseline. These women were more likely to report sleep difficulty, nervousness, depressed mood, and decreased mobility and activities of daily living than nonusers. Benzodiazepine use was associated significantly with greater decline in performance during follow-up than nonuse in all three physical performance measures. Physical performance of long-term users (more than three years before baseline) declined significantly more than that of recent users and past users. Recent users showed greater decline than nonusers, though this difference was not significant, and past users had no decline. A dosage response was noted in benzodiazepine users, with a greater decline noted in women taking higher-than-recommended dosages, but not in women taking the minimum dosage or lower.

Benzodiazepine users were 2.64 times more likely than nonusers to have a significant decline in physical performance over four years, an association that persisted in women without disability at baseline.

This study provides evidence that benzodiazepine use in older women increases the risk for decline in physical performance—even in those without antecedent physical disability—particularly with higher-than-recommended dosages and long duration of use. The authors were able to control for enough confounding factors, particularly differences in indication for benzodiazepine use, to suggest that decline in physical function results from benzodiazepine use rather than vice versa. The decline in physical function may be mediated by such benzodiazepine effects as sedation and muscle relaxation.