Incident Use of a Potentially Inappropriate Medication and Hip Fracture in Community-Dwelling Older Persons With Alzheimer’s Disease

Background: Potentially inappropriate medications (PIMs) increase the risk of adverse drug reactions and events and have been associated with greater health care service use, such as an increased risk of hospitalization. Objective: The aim of this study is to evaluate the association between PIM use and hip fractures in a nationwide cohort of community-dwelling persons ≥65 years old with Alzheimer’s disease (AD). Methods: The study, which is based on the Finnish nationwide MEDALZ cohort, included all persons diagnosed with AD between 2005 and 2011 (n = 70 718). After a 1-year washout period for PIM use and exclusion of persons with previous hip fracture before AD diagnosis or those who had been hospitalized, we included 47 850 persons ≥65 years old with AD. PIM use was identified using Finnish criteria. Associations between PIM use and hip fracture were analyzed with Cox proportional hazards regression. Results: Of the study population, 12.3% (n = 5895) initiated PIMs during the follow-up (maximum follow-up 2921 days and total number of person-years 139 538.7). Of those, 103 (1.7%) persons had hip fractures during the PIM use period. The results suggest that PIM use was only associated with an increased risk of hip fracture with incident PIM use (adjusted hazard ratio = 1.31; 95% CI = 1.06-1.63; P = 0.014). Conclusions: PIM use is associated with increased risk of hip fracture when a person uses PIMs for the first time. However, the association between PIM use and hip fracture should be investigated more comprehensively in future studies.