RESUMEN
BACKGROUND: We conducted a study to investigate the role of health insurance plans on biosimilar adoption among commercially insured patients in the USA. Flexible and rigid health plans may exhibit differing biosimilar coverage due to variations in cost considerations, formulary design, and provider networks. OBJECTIVE: To identify the characteristics of switchers and biosimilar initiators for six biologic-biosimilar pairs. METHODS: Using claims data from 2015 to 2019, we implement sequential regression models to assess the role of health plans on biosimilars adoption. FINDINGS: We found that low-flexibility plans, such as Health Maintenance Organization (HMOs) and Exclusive Provider Organization (EPOs), are more likely to have patients who are switchers and/or biosimilar initiators. CONCLUSION: Our findings highlight the importance of health insurance plan design in promoting biosimilar uptake.