Drug use in persons with and without Alzheimer's disease aged 90 years or more

BACKGROUND: increasing number of persons reach very high age but few studies have investigated their drug use patterns. OBJECTIVE: to compare drug use among persons with Alzheimer's disease (AD) aged ≥90 years to persons without AD with similar age and to younger persons with AD. DESIGN: register-based data were from the MEDALZ cohort including all community-dwelling persons diagnosed with AD 2005-11 in Finland. They were identified from Special Reimbursement register. One comparison person without AD was matched with age-, gender- and region of residence. Persons with AD were divided to those aged ≥90 years (N = 3,319) and <90 years (N = 63,896) at the time of AD diagnoses. Drug use was analysed during a 6-month period after AD diagnosis. Logistic regression models were constructed to compare prevalence of drug use. RESULTS: compared to comparison persons without AD with similar age, persons with AD aged ≥90 years were more likely to use antipsychotics (comorbidity adjusted odds ratio [aOR] 4.84, 95% CI 4.07-5.75; CI, confidence intervals) and antidepressants (aOR 2.45, 95% CI 2.14-2.80). In addition, persons with AD used more likely preventive drugs such as statins (aOR 1.20, 95% CI 1.04-1.38) and bisphosphonates (aOR 1.33, 95% CI 1.13-1.57). Compared to younger persons with AD, those aged ≥90 years were more likely to use psychotropic drugs (55.6% vs. 48.4%, aOR 1.30, 95% CI 1.21-1.39), including antipsychotics (aOR 1.40, 95% CI 1.28-1.52) and BZDRs (aOR 1.34, 95% CI 1.25-1.45). CONCLUSIONS: the vulnerable oldest persons with AD receive a substantial burden of psychotropics.