Effect of Medication Copayment on Adherence and Discontinuation in Medicare Beneficiaries with Type 2 Diabetes: A Retrospective Administrative Claims Database Analysis

Abstract

IntroductionNonadherence to antihyperglycemic agents (AHAs) increases the incidence of morbidity and mortality, as well as healthcare-related costs, in patients with type 2 diabetes (T2D). This study examined the association between medication copayment and adherence and discontinuation among elderly patients with T2D who use generic versus branded AHAs.MethodsA retrospective, observational cohort study used Medicare administrative claims data (index period: 1 June 2012 to 31 December 2013). Drug copayments were measured as the copayment of the index medication for a 30-day supply after patients met their plan deductible. Patients were stratified into a branded or generic cohort based on the index medication. Adherence was measured by the proportion of days covered (≥ 80%) and discontinuation by a treatment gap of > 60 days in 10 months during the follow-up period. Poisson regressions were conducted for medication adherence and discontinuation, while controlling for demographic, clinical, and comorbid conditions.ResultsOverall, 160,250 patients on AHA monotherapy were included in the analysis; 131,594 (82%) were prescribed a generic and 28,656 (18%) a branded AHA with a mean copay of $6 and $41, respectively. Increases in copayment increased nonadherence and discontinuation for branded medications but not for generic AHA medications. In both cohorts, elderly patients (≥ 75 years of age) had a lower risk of nonadherence and discontinuation. Black patients had a higher risk of nonadherence or discontinuing medication. Patients having more frequent inpatient, emergency room, and/or physician visits were at higher risk of nonadherence or discontinuing therapy in the branded and generic cohorts (P < 0.001).ConclusionThe impact of drug copayment on adherence and discontinuation varied considerably between branded and generic AHAs. Medicare patients taking branded AHAs had a higher risk of nonadherence with increasing copayment and were more likely to discontinue medication, whereas this association was not observed in patients taking generic medications.FundingMerck & Co, Inc., Kenilworth, NJ, USA.Plain Language SummaryPlain language summary available for this article.Electronic supplementary materialThe online version of this article (10.1007/s13300-018-0489-y) contains supplementary material, which is available to authorized users.

A cross-sectional study clarifying profiles of patients with diabetes who discontinued pharmacotherapy: reasons and consequences.

“…In addition to adherence, persistence with medication is another critical issue. Some studies using administrative claims databases of relatively large samples presented speci c rates of persistence [8,9]. Comparative analysis across types of drugs were also reported [10] and could be applied in selecting medications to lower the risk of discontinuation.…”

The Role of the Clinical Pharmacist in a Preventive Cardiology Practice

“…Investigating the threshold at which medication nonadherence significantly rises reveals a strikingly low cost: at patient out-of-pocket expenses <$50 per month. [26][27][28] In the realm of novel cardiovascular pharmacotherapy (ie, PCSK9i, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, etc), which have been repeatedly proven to reduce CVD events and hospital readmissions and extend longevity, patient affordability and therefore adherence is in jeopardy. This report highlights cost avoidance strategies as one of many roles of a clinical pharmacist in cardiovascular care, but arguably the most impactful.…”

“…Given rising medication costs, more frequent use of novel (and expensive) cardiovascular pharmacotherapy, and adherence rates closely linked to drug costs, interventions that improve patient access to medications via cost reduction are of monumental importance. Medication adherence is inversely affected by medication cost, [25][26][27][28] and cost savings strategies improve access to medications, surrogate marker outcomes and their goal attainment, and hospital readmission rates. [15][16][17][18] Thus, reducing medication out-of-pocket expense is of vital importance to enhance medication access for patients, improve adherence rates, and as a result, potentially improve clinical outcomes.…”

Association of daily copayments with use of hospital care among medicare advantage enrollees

“…Most Medigap policies eliminate inpatient cost sharing altogether, which is a much larger change than our study and presumably less relevant for Medicare Advantage, purchasing Medigap reduces or eliminates cost sharing for many other services besides inpatient care, and the effect of cost sharing may differ in Medicare Advantage given supply-side, managed care constraints that are not found in traditional Medicare. Recent studies related to Medicare and Medicare Advantage focused on prescription drug use and adherence [12,13], skilled nursing facility utilization [14], or Medicare Advantage enrollment [15]. The lack of inpatient utilization studies in the broader Medicare fee-for-service and Medicare Advantage programs is an important gap since hospital costs are the largest component of Medicare spending and the Medicare Part A deductible is the largest single out-of-pocket expense in the traditional Medicare benefit structure, $1340 in 2018 [16].…”