40 PREVALENCE OF DRUG-DRUG INTERACTIONS IN OLDER COMMUNITY-DWELLERS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Abstract Background Polypharmacy (regular use of ≥5 medicines) is common in the older population and is an independent risk factor for Drug-Drug Interactions (DDIs). We conducted a systematic review and meta-analysis to summarise the prevalence of DDIs in older (≥65years) community-dwellers. Methods An electronic database search was conducted in PubMed and EMBASE. Observational studies published in English between 01/01/2010-10/05/2021 reporting DDI prevalence in community-dwellers aged ≥65years were included. Nursing home and inpatient hospital studies were excluded. Articles were independently double screened for eligibility. Data were independently extracted, 20% extracted in duplicate. Quality assessment was performed using the Joanna Briggs Institute critical appraisal tool. Prevalence estimates and 95% confidence intervals (CI) are presented. All analyses were performed using the metafor package(v3.0.2) in R(v4.1.2). (PROSPERO:CRD42020216686). Results 5144 unique articles were identified. 33 studies involving 17,011,291 community-dwellers aged ≥65years (age range 65-103) met inclusion criteria. 22 studies measured DDIs broadly classified as (potentially) clinically important. DDI identification methods varied across studies: 5 used Micromedex®; 3 used the 2015 AGS Beers criteria®; 3 used Lexi-Interact®; 2 used drugs.com; 6 used multiple methods; and 14 used a unique method. 31 studies reported DDI prevalence at the study participant level; estimates ranged from 0.8% to 90.6%. 26 studies were qualitatively synthesised and 7 studies were eligible for meta-analyses. In a meta-analysis of 3 studies (n=1122) using Micromedex®, DDI prevalence in older (≥65years) community-dwellers was estimated to be 57.8% (95%CI: 52.2-63.2%; I2 69.6%, p<0.01). In a meta-analysis of 2 studies (n=809,113) using Lexi-Interact®, the estimated prevalence was 30.3% (95%CI: 30.2-30.4%; I2 6.8%). In a meta-analysis of 2 studies (n=947) using the 2015 AGS Beers criteria®, the estimated prevalence was 16.6% (95%CI: 5.6-40.2%; I2 97.5%, p<0.01). Conclusion DDIs are prevalent among older community-dwellers; however, the methodology used to estimate these events varies considerably. A standardised method is needed to allow meaningful measurement of DDI prevalence in this population.