Psychotropic drugs and risk of recurrent falls in ambulatory nursing home residents.

Although psychotropic drug use has been associated with increased risk of falls in long-term care settings; this association may be confounded by the high prevalence of dementia and depression and other fall risk factors. This question was addressed in a prospective cohort study of recurrent falls among 282 ambulatory residents of 12 Tennessee nursing homes during 1991-1992. Eligible subjects were > or = 65 years of age, ambulatory, able to provide study data, and expected to remain in the nursing home for > or = 3 months. Baseline data collected for each cohort member included symptoms of dementia (cognitive impairment and behavior problems) and depression, medication use, and other potential fall risk factors. Falls were ascertained from facility incident reports and nursing home charts. During follow-up, 111 residents had > or = 2 falls, an incidence rate of 54.9 recurrent falls per 100 person-years. With the use of Cox proportional hazards modeling, the authors found incidence density ratios (95% confidence intervals (Cl)) showing that the following risk factors were independently associated with recurrent falls: age > or = 75 years (1.66 (1.01-2.72)); > or = 4 assisted activities of daily living (1.94 (1.09-3.47)); middle (2.08 (1.20-3.61)) and upper (2.54 (1.44-4.49)) tertiles of balance impairment; fall in the 90 days preceding assessment (2.01 (1.32-3.06)); and upper tertile of behavior problems (1.65 (1.03-2.64)). The rate of recurrent falls increased tenfold as the number of these risk factors increased from 0 to 5 (21.4 to 231.5 per 100 person-years, p < 0.0002). After controlling for symptoms of dementia and depression and other fall risk factors, the incidence density ratio for recurrent falls in baseline regular psychotropic drug users (n = 178) compared with nonusers (n = 104) was 1.97 (95% Cl 1.28-3.05). Within groups defined by number of other independent fall risk factors present, regular psychotropic users had a recurrent fall rate that was greater than that for nonusers: 44.1 versus 22.9 per 100 person-years (p = 0.03) in the low risk (< or = 2 factors) group and 98.7 versus 64.3 (p = 0.08) in the high risk (> 2 factors) group. The attributable risk of recurrent falls for regular psychotropic drug users was 36%, which suggests optimal management of psychopharmacotherapy is an essential component of fall prevention programs for ambulatory nursing home residents.