A payer perspective of the costs of urinary tract and skin and soft tissue infections in adults with diabetes and the relationship to oral antidiabetic medication nonadherence

Abstract

BACKGROUND: Controlling costs and improving quality outcomes are important considerations of the triple aim in health care. Medication adherence to oral antidiabetic (OAD) medications is an outcome measure for those with diabetes. However, there is little research reporting the costs associated with OAD medication adherence among adults with diabetes and comorbid infections. OBJECTIVE: To provide nationally representative cost and utilization estimates from a payer perspective of 2 common comorbid infections: urinary tract infection (UTI) and skin and soft tissue infection (SSTI) among adults with diabetes in relation to OAD medication nonadherence to quantify cost per outcome. METHODS: A retrospective observational study for years 2010-2015 used longitudinal panel data in the public domain from the Medical Expenditure Panel Survey (MEPS). The study included individuals aged ≥ 18 years with diabetes (excluding gestational diabetes) who were prescribed OAD medications and then stratified by infection status, that is, without infection versus with UTI and/or SSTI. Outcomes measured included medication adherence, defined as medication possession ratio (MPR); treated prevalence of UTI and SSTI; and associated direct medical costs paid by insurers. RESULTS: 4,633 adults with diabetes were included; of those, 12% reported a UTI or SSTI, with the weighted sample representing 2.2 million U.S. residents. The mean MPR was 0.61 and 0.63 in the infection and noninfection groups, respectively. Less than 35% in each group were adherent to OAD medications. Having a UTI or SSTI increased the adjusted total health expenses by 53.7% (P < 0.001), but adherence to OAD medications did not significantly affect total health care costs. CONCLUSIONS: In adults with diabetes, a UTI or SSTI diagnosis did not influence medication adherence to OAD medication but increased health care utilization and costs significantly.