Central nervous system medication use and incident mobility limitation in community elders: the health, aging, and body composition study

Purpose To evaluate whether CNS medication use in older adults was associated with a higher risk of future incident mobility limitation. Methods This 5-year longitudinal cohort study included 3055 participants from the health, aging and body composition (Health ABC) study who were well-functioning at baseline. CNS medication use (benzodiazepine and opioid receptor agonists, antipsychotics, and antidepressants) was determined yearly (except year 4) during in-home or in-clinic interviews. Summated standardized daily doses (low, medium, and high) and duration of CNS drug use were computed. Incident mobility limitation was operationalized as two consecutive self-reports of having any difficulty walking 1/4 mile or climbing 10 steps without resting every 6 months after baseline. Multivariable Cox proportional hazard analyses were conducted adjusting for demographics, health behaviors, health status, and common indications for CNS medications. Results Each year at least 13.9% of participants used a CNS medication. By year 6, overall 49% had developed incident mobility limitation. In multivariable models, CNS medication users compared to never users showed a higher risk for incident mobility limitation (adjusted hazard ratio (Adj. HR) 1.28; 95% confidence interval (CI) 1.12-1.47). Similar findings of increased risk were seen in analyses examining dose- and duration-response relationships. Conclusions CNS medication use is independently associated with an increased risk of future incident mobility limitation in community dwelling elderly. Further studies are needed to determine the impact of reducing CNS medication exposure on mobility problems. Copyright (C) 2009 John Wiley & Sons, Ltd.