Impact of potentially inappropriate medication use on healthcare utilization and mortality in older adults with multimorbidity

Aim Ensuring medication safety continues to be a challenging problem in older adults with multiple chronic diseases. This study aims to investigate the association of potentially inappropriate medication use with healthcare utilization and mortality and also explore the influence of pay-for-performance programs in multimorbid older adults in Taiwan. Method The study population was comprised of older adults aged 65 years or older with multimorbidity and at least one outpatient drug prescription in 2018. Healthcare utilization (outpatient clinic visit, emergency room visit, hospitalization) and medical cost at six months were analyzed using general linear model (continuous) and multiple logistic regression (categorical). Mortality at one year was determined using Cox-proportional hazard regression model. Separate analyses were performed for disease subgroups with pay-for-performance programs. Results The prevalence of PIM use was 85.6% in the multimorbid older adult population. PIM use was associated with increased outpatient clinic visit (β=0.0591, SE 0.0008, p<0.0001), emergency department visit (aOR 1.103, 95% CI 1.094-1.112, p<0.0001), hospitalization (aOR 1.131, 95%CI 1.120-1.143, p<0.0001), and total medical cost (β=0.0507, SE 0.0024, p<0.0001). After adjusting for covariates, PIM use had higher risk of mortality at one year (aHR 3.509, 95%CI 3.285-3.748, p<0.0001). The positive association of PIM use with healthcare utilization attenuated with enrollment in pay-for-performance program. Conclusion: PIM use was significantly associated with increased risk of healthcare utilization and mortality in older adults with multimorbidity, which indicated the need for selection of safer drug therapy or alternatives in this vulnerable population.