Kidney Function, Polypharmacy, and Potentially Inappropriate Medication Use in a Community-Based Cohort of Older Adults

Abstract

Background: Chronic kidney disease (CKD) afflicts many older adults and increases the risk for medication-related adverse events. Objective: The aim of this study was to assess the prevalence and associated morbidity and mortality of polypharmacy (use of several medications concurrently), and potentially inappropriate medication (PIM) use in older adults, looking for differences by CKD status. Methods: We quantified medication and PIM use (from Beers criteria, the Screening Tool of Older People’s Prescriptions, and Micromedex®) by level of estimated glomerular filtration rate (eGFR) for participants aged 65 years or older attending a baseline study visit in the Atherosclerosis Risk in Communities study (n =6392). We used zero-inflated negative binomial and Cox proportional hazards regressions to assess the relationship between baseline polypharmacy, PIM use, and subsequent hospitalization and death. Results: Mean age at baseline was 76 (± 5) years, 59% were female, and 29% had CKD (eGFR < 60 ml/min/1.73 m2). Overall, participants reported 6.1 (± 3.5) medications and 2.3 (± 2.2) vitamins/supplements; 16% reported ≥ 10 medications; 31% reported a PIM based on their age. On average, participants with CKD reported more medications. A PIM based on kidney function was used by 36% of those with eGFR < 30 ml/min/1.73 m2. Over a median of 2.6 years, more concurrent medications were associated with higher risk of hospitalization and death, but PIM use was not. While those with CKD had higher absolute risks, there was no difference in the relative risks associated with greater numbers of medications by CKD status. Conclusion: Polypharmacy and PIM use were common, with greater numbers of medications associated with higher risk of hospitalization and death; relative risks were similar for those with and without CKD.