Higher out-of-pocket costs were linked to an increased risk of medication nonadherence in patients with autoimmune conditions, according to data presented at AMCP 2022.

“Biologic specialty drugs...are expensive therapeutic classes to health plan insurance payers,” researchers noted. “The reported [anti-inflammatory] adherence rates are highly variable (9.4%-94%), due to many factors.”

Authors gathered 2017-2019 pharmacy claims for approximately 25 million Americans. Participants were included if they were continuously rolled in health plan coverage for at least 1 year, were at least 18 years of age, and had at least 2 anti-inflammatory claims spanning at least 2 dates of service. The final sample included 125,118 patients.

“The market size of [anti-inflammatory] drug cost in the study grew significantly from 14.2% to 19.2% of total pharmacy cost between 2017 and 2019,” authors said. Costs annually increased by about 10%, or $5000, for each patient taking anti-inflammatory medication for autoimmune conditions.

Patients were considered adherent if they met an 80% threshold of proportion of days covered annually. Average nonadherence rates were 41.8% in 2017, 41.1% in 2018, and 38.6% in 2019. Higher out-of-pocket per day cost was associated with greater risk of nonadherence, with an odds ratio of 3.5 (95% CI 3.4-3.7) for patients whose out-of-pocket costs per day exceeded $30 vs patients whose out-of-pocket costs per day were $30 or less.

Researchers estimated lowering out-of-pocket per day costs by 10% would result in a 2.2% improvement to proportion of days covered.

“Out-of-pocket per day cost negatively impacts autoimmune anti-inflammatory [medication adherence],” authors concluded.

Reference:
Wu Y, Brown-Gentry K, Lockhart K, Hunter B, Prasala K. Assess out-of-pocket cost to impact medication adherence for patients with autoimmune disease conditions. Poster presented at: AMCP 2022; March 29-April 1, 2022; Chicago, IL.