Study: Higher Out-of-Pocket Costs Lead to Nonadherence

A literature review by AmerisourceBergen's Xcenda identifies a link between high cost sharing and patient nonadherence to medication regimens.

The higher the cost-sharing burden health plans place on patients, the more impact there is on adherence and persistence, according to a recent study by Xcenda published in the Journal of Managed Care + Specialty Pharmacy. But the study found little evidence on the impact of high cost-sharing on outcomes.

“Across different geographical regions, different kinds of patients taking different kinds of medications and indications, it was consistent that increased cost sharing was related to decreased treatment adherence. That is a real-life impact,” Nicole Fusco, Sc.D., manager, evidence synthesis & modeling at AmerisourceBergen's Xcenda said in an interview with Formulary Watch.

Xcenda researchers conducted a systematic review of literature published between January 2010 and August 2020 to identify the relationship between cost-sharing and medication adherence, clinical outcomes, healthcare resource utilization, and healthcare costs. They included observational studies or randomized controlled trials conducted in the United States, and excluded trials of diagnostic tests or medical care

They found 79 articles, with most studies, 71 of 79 (90%), reporting the relationship between cost-sharing and treatment adherence, persistence and/or discontinuation. The relationship between higher out-of-pockets costs and adherence, persistence, and discontinuation results was relatively consistent across included studies. The majority of publications found that increased cost-sharing was associated with worse adherence (84% of studies), persistence (79% of studies), or discontinuation (58% of studies).

The review was across therapeutic areas, but Fusco said the nonadherence related to cost-sharing may have appeared to be more severe in the cardiovascular area. “This makes intuitive sense. A lot of the medications for cardiovascular disease, such as for hypertension, are preventive with long-term outcomes,” she said.

Just 16 (20%) of the reviewed studies reported data on cost-sharing and healthcare resource utilization or medication initiation, 11 (14%) on cost-sharing and healthcare costs, and 6 (8%) on cost-sharing and clinical outcomes.

“We were limited in the ability to look longitudinally at patients to see how adherence would, in fact, impact their actual health. But there’s certainly the rationale that if patients are supposed to be taking a particular therapy, and they do not take it the way they’re supposed to take it, then that might have real health impacts,” Kristin Kistler, Ph.D., associate director, evidence synthesis & modeling at Xcenda, said in an interview.

Among studies examining clinical outcomes, cost-sharing was associated with worse outcomes in one study and the remaining three found no significant differences. Regarding healthcare resource utilization, higher-cost-sharing trended toward decreased outpatient and increased inpatient utilization.

In the paper, researchers point out that cost-sharing may increase total healthcare costs because in the long term, patients in poorer health need medical treatments, utilization, and procedures that could have been avoided.

“A surprise takeaway was that there really isn't any benefit to passing on costs to patients, when looking at overall costs. There seems to be a neutral impact on cost savings. Costs are passed on to patients and benefit design is developed with the intent of saving money, hoping that patients will make more thoughtful choices about which drugs, maybe going for generics, or maybe not seeking services that are aren't necessary. And instead of reducing costs, overall, there really seemed to be no benefit,” said Kimberly Ruiz, EdM, director, evidence Synthesis & modeling at Xcenda.

The review was limited to published studies. Results from abstracts and unpublished results were not included. Second, a broad definition for cost-sharing was used. The type of cost-sharing and magnitude were not the same across the studies. Additionally, the outcome definitions varied, making comparisons across publications difficult.