P-515: Hip fracture incidence in persons who initiate antiepileptic drugs after Alzheimer's disease diagnosis and in matched non-users

摘要

Introduction: It is unclear whether antiepileptic drugs (AEDs) are associated with increased hip fracture (HF) risk in persons with Alzheimer's disease (AD). Methods: The Medication and AD (MEDALZ) cohort includes all Finnish community dwellers with clinically verified diagnosis of AD in 2005-2011. Using the Prescription Register, we identified cohort members who initiated AEDs after diagnosis applying a 1-year washout period. Each user was matched to 2 non-users by sex-, age (± 1 year) and time since AD diagnosis (± 183 days) using incidence-density sampling. From both groups, we excluded persons with HF before index date (date of AED initiation in users and matching date in non-users). We identified the first HF after index date through ICD-10 codes S72.0, S72.1 and S72.2 in the Hospitalization and Causes of Death Registers. Persons were followed-up until first HF, death, hospitalization/institu-tionalization lasting > 90 days, AED initiation in non-users, or study end (31 December 2015), whichever occurred first. Using Poisson regression, we calculated age- sex- adjusted Incidence Rates (IRs) and Incidence Rate Ratios (IRRs), with 95% Confidence Interval (95% CI). Results: In both 5522 users and 11,044 non-users, women were 65% and median age was 81 years. Age-sex-adjusted IR was higher in users (5.3 per 100,000 person-years; 95% CI 4.70-6.00) than in non-users (4.4; 4.0-4.9); IRR was 1.18 (1.04-1.35). Conclusions: HF incidence was higher in users than in non-users. We will conduct multivariable analyses to account for potential con-founders, health status and use of other fall-related drugs.