Healthcare Expenditures Among Older Adult with Polypharmacy in the United States: A Propensity Score-Matched Cross-Sectional Study

OBJECTIVES: It is well-recognized that polypharmacy leads to increased healthcare utilization and financial burden on patients. However, few studies have quantified the burden using rigorous study design. The aim of this study was to quantify the impact of polypharmacy on health care expenditure in older adults.

METHODS: Our study included adults aged ≥65 years from 2018-2021 Medical Expenditure Panel Survey (MEPS). Polypharmacy was defined as using ≥5 prescription medications simultaneously. Propensity score matching (PSM) that incorporated demographic, socioeconomic status, and over 60 comorbidities was used to balance patient characteristics between those with and without polypharmacy. Healthcare expenditures overall, by service types (inpatient, outpatient, emergency, office-based visits, prescriptions, home health care, others), and by payers (out-of-pocket, Medicare, Medicaid, private insurance, others) were examined using two-part models. The impact of polypharmacy on self-reported cost-related medication adherence was examined.

RESULTS: We included 9,846 participants, with mean age of 74.0 years (95% CI: 73.8-74.2) and 55.8% female. After PSM, the two groups were well-balanced in all characteristics. Polypharmacy was associated with an extra of $4344.9 healthcare expenditures, mainly attributed to office-based visits ($1302), out-patient care ($928) and prescription costs ($1171). The extra expenditures fell mainly on Medicare ($3848) and private insurance ($1382). Polypharmacy resulted in $589 more out-of-pocket expenditures and was associated with significantly higher risk of cost-related nonadherence (odds ratio, 1.9 [1.4-2.7]).

CONCLUSIONS: Polypharmacy was associated with substantial healthcare expenditures. The increase in expenditures was not limited to prescription medication and affected patients and the public and private health insurance. The study emphasized the financial burden of polypharmacy and called for effective interventions to tackle polypharmacy in older adults. After rigorously controlling for patient difference, the study provided accurate estimates on the costs of polypharmacy, which may guide cost-effectiveness evaluation of interventions to reduce polypharmacy.