A new study has determined that medication copayments may represent a structural barrier to medication adherence among poorer patients with pulmonary arterial hypertension (PAH).

The study, published in the Journal of the American Heart Association, noted specifically that those with high copayments had decreased adherence to prostanoids and to combination therapy.

“Given the high cost of pulmonary vasodilators, we undertook this study to understand how medication copayment and household income relate to adherence to pulmonary vasodilator therapy for PAH,” the authors wrote. “Our dual hypotheses were that (1) higher copayment and (2) annual household income would be associated with decreased adherence to disease-specific medications in individuals with PAH.”

Continue Reading

The research team employed commercially available administrative claims data from Optum’s De-identified Clinformatics Data Mart on 4025 adults in the US with PAH to find associations between medication copayment and adherence to pulmonary vasodilator therapy. Annual household income was categorized in the Optum database as less than $40,000, $40,000 to $49,999, $50,000 to $59,999, $60,000 to $74,999, $75,000 to $99,999, and more than $100,000.

Read more about PAH therapies

Median 30-day copayments ranged from $11.05 to $60.08, depending on the specific medication.

The results showed that annual household income was not associated with better or worse medication adherence. However, higher copayments were significantly associated with poorer medication adherence to prostanoids and combined therapy with endothelin receptor antagonists and phosphodiesterase type-5 inhibitors compared with low copayments.

The authors speculate that patients who are underinsured might find themselves with high copayments and might therefore prioritize more basic needs over medications in a context of limited resources. They note that clinician awareness of copayments as barriers to medication adherence in PAH could inform shared decision making when initiating therapy with these patients.


Schikowski E, Swabe G, Chan SY, et al. Association between copayment and adherence to medications for pulmonary arterial hypertension. J Am Heart Assoc. Published online November 12, 2022. doi:10.1161/JAHA.122.026620