Number-dependent association of potentially inappropriate medications with clinical outcomes and expenditures among community-dwelling older adults: A population-based cohort study

Aims The aim of this study was to investigate the prevalence of potentially inappropriate medication (PIM) prescribing and its number-dependent association (PIM = 1, 2, >= 3) with all-cause hospitalizations, emergency department (ED) visits, and medication expenditures in Beijing, China. Methods A retrospective cohort analysis was conducted to analyse PIM prescribing in community-dwelling older adults aged >= 65 years within the Beijing Municipal Medical Insurance Database (data from July to September 2016). The prevalence of PIMs was estimated based on the 2015 Beers Criteria. Logistic models were utilized to investigate the associations between PIM use and all-cause hospitalizations and ED visits. Generalized linear models with the logic link and gamma distribution were used to analyse associations between PIM use and medication expenditures. Results Among the 506 214 older adults, the prevalence of PIM was 38.07%. After adjusting for covariables, prescribing two and three or more PIMs was associated with increased risks of hospitalizations (PIM = 2: odds ratio [OR] 1.34, 95% confidence interval [CI]: 1.22-1.47; PIM >= 3: OR = 1.47, 95% CI: 1.32-1.63) and ED visits (PIM = 2: OR = 1.29, 95% CI 1.12-1.48; PIM >= 3: OR = 1.23, 95% CI: 1.04-1.44). Exposures to two and three or more PIMs were associated with higher medication expenditures for inpatient visits (PIM = 2: incidence rate ratio [IRR] = 1.08, 95% CI 1.01-1.16; PIM >= 3: IRR = 1.18, 95% CI: 1.08-1.28). Vasodilators were the most frequent PIM prescribing group among patients who were hospitalized or had to visit the ED. Conclusions PIMs were prescribed at a high rate among community-dwelling older adults in Beijing. Two or more PIMs were associated with increased risks of hospitalizations, ED visits, and increased inpatient medication expenditures. Effective interventions are needed to target unnecessary and inappropriate medications in older adults.