Social, political, and economic determinants of access to biologics: A scoping review of structural determinants in the clinical disparities literature

Background: The number of biologics among new medication approvals is increasing. Social, political, and economic factors influence access to these expensive medications. Disparities in access to new medications can exacerbate health disparities. The notion of “structural determinants” provides a theoretical framework for broadly evaluating the integration of upstream social, political, and economic determinants in the clinical study of access. Objective: To review the literature on access to FDA approved biologic medications with particular focus on the integration of social, political, and economic determinants into study design and interpretation. Methods: We used PRISMA guidelines to review studies on racial and socioeconomic disparities in biologic access through August 2020. We assessed whether the design or interpretation of studies considered key economic determinants of access: the biologics supply chain, trade agreements, patents, drug research and development, insurance reimbursement, and non-insurance drug policies. Results: 100 studies met our inclusion criteria. Sixty-six studies considered insurance reimbursement, but trade law, patents, and other key economic determinants were rarely considered. The literature focuses on a small number of older biologics. Conclusions: A small number of studies model the integration of structural determinants into clinical research on access to biologics, but overall this literature has many limitations and lacks integration of structural determinants. Increased interdisciplinary collaboration, availability of manufacturer data, and use of disease registries can help create structurally grounded understandings of the relationship between the political economy of expensive medications and clinical disparities.