A recent study suggests that an increase in prescription co-payments could negatively impact medication adherence, especially in low-income areas.
The study, published in the (italics) Journal of General Internal Medicine, (end italics) was funded by GlaxoSmithKline, a research-based pharmaceutical and healthcare company with U.S. headquarters in Philadelphia.
The study was a multi-year retrospective analysis of insurance claims data for patients with Type 2 diabetes or congestive heart failure.
The analysis showed an inverse relationship between co-payment and medication adherence for most - although not all - of the medication classes. Patients in low-income areas were more sensitive to co-payment changes than patients in high- or middle-income areas.
Key findings include:
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For each medication class, individuals in high-income areas were consistently more adherent than individuals in low-income areas.
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For both diabetes and CHF, there was a notable decrease in medication adherence across all drug categories in response to a 10-percent increase in drug co-payment, with the largest decreases in adherence occurring in the lowest income groups.
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Adherence to statins was particularly sensitive to income, with diabetes patients in the highest-income group being more than 20 percent more adherent than those in the lowest-income category.
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In high-income areas, CHF patients were more than 30 percent more adherent to statins than their counterparts in low-income areas. CHF patients in high-income areas were also substantially more adherent to beta-blockers than CHF patients in low-income areas.
"Based on our analysis, it is likely that increased co-payments, intended to control costs, will exacerbate the disparities seen across socioeconomic groups," said Michael Chernew, a professor in the Department of Health Care Policy at Harvard Medical School and one of the authors of the study.
The study complements the results of earlier studies from GSK's Health Management Innovations team which indicate that barriers to medication access should be removed to improve adherence, better manage chronic conditions, improve health and lower total healthcare costs.
"We must encourage employers and health plans to develop benefit strategies that improve the health of all patients - especially those with chronic diseases - which can lead to lower total healthcare costs," said Michael C. Sokol, MD, medical director for GSK's Health Management Innovations team and one of the authors of the study.