The impact of medical insurance on health care access and quality for people with multiple sclerosis in the United States: A scoping review

Abstract

Background: In the United States, health insurance coverage and quality mediate access to health care, a key social determinant of health. Objective: To perform a scoping review regarding the impact of insurance coverage and benefit design on health care access and both clinical and quality of life outcomes in people with MS (pwMS). Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines were followed. A literature search was conducted from January 2010 to February 2022. Included studies were in English, peer-reviewed, US-based, and evaluated elements of insurance and their relationship with access and quality outcomes for adult pwMS. Results: Our search identified 1619 articles, of which 32 met inclusion criteria. Privately insured pwMS were more likely to be on disease-modifying therapy (DMT). Increased out-of-pocket spending was associated with lower DMT adherence and greater discontinuation rates. Access to specialty pharmacy programs was associated with improved DMT adherence. Conclusion: Health insurance coverage and design strongly influences health care for pwMS in the United States and may be a modifiable social determinant of health. Increased pharmaceutical cost-sharing is associated with declines in DMT utilization and adherence. Further study is needed to better characterize the impacts of other core elements of health insurance, including prior authorization requirements and step therapy.