Objective: To examine the relationship between antipsychotic drug prescription, cognitive impairment, and disturbed behavior in a large population of elderly people in residential and nursing homes over time and to identify possible adverse consequences of their use.
Design: Two censuses of the residential and nursing home population aged 65 years and older in the UK county of Leicestershire carried out in 1990 and 1997.
Materials and Methods: A questionnaire was completed by care staff for each resident, including information on demographic details, physical functioning, cognitive impairment, behavior disturbance, urinary incontinence, falls, mobility, daytime alertness (1997 only), and prescribed medication. Univariate and multivariate logistic regression models were used to investigate changes between 1990 and 1997 adjusting for other factors.
Results: Census response rates (homes) were 95% in 1990 and 73% in 1997. The prevalence of staff-rated moderate or severe cognitive impairment increased from 38.0% in 1990 to 44.3% in 1997. The prevalence of staff-rated disturbed behavior decreased from 11.8% in 1990 to 10.4% in 1997. Cognitive impairment was strongly associated with disturbed behavior in both years. The prescription rate of antipsychotic drugs increased from 17.8% in 1990 to 21.9% in 1997. There was no significant change in the prescription rates to cognitively impaired residents between 1990 and 1997 (29.1% vs. 30.7%). In residents without cognitive impairment, the prescription rate rose from 10.7% to 15.0%. Antipsychotic drug use was independently associated with: younger age, type of home (1990 only), cognitive impairment, offensive behavior, lower ADL dependency (1990 only), antidepressant drug use, reported urinary incontinence, and greater mobility (1990 only) and falls (1997 only). There was no association with increased liability to falls or drowsiness. The association with falls was stronger in the cognitively unimpaired residents, antipsychotic drug use was not associated with urinary incontinence in 1997, and there was an association with increased drowsiness in that year's residents. There was no association between antipsychotic drug use and sleep/conscious level in 1997.
Conclusions: The only significant change in antipsychotic drug prescribing practice in this population over the period covered by this study was an increase in the prescription rate in cognitively unimpaired residents in 1997, possibly related to mental hospital closures. Urinary incontinence was the principal problem. Regarding adverse effects of antipsychotic drug use observed in the group as a whole, there was an association with urinary incontinence in 1990 and liability to falls in 1997. Changes in the adverse effects associated with antipsychotic drug use over time in the cognitively unimpaired residents may be a function of the increasing physical frailty of this population.
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