Systematic reviews reveal unrepresentative evidence for the development of drug formularies for poor and nonwhite populations

Abstract 

Objective

To explore implications of using systematic drug class reviews to develop U.S. Medicaid drug formularies. We assess racial/ethnic, gender, and socioeconomic status (SES) concordance between Medicaid populations and studies synthesized in Drug Effectiveness Review Project (DERP) systematic reviews.

Study Design and Setting

Review of 32 DERP systematic reviews for subpopulation reporting/analysis and concordance with Medicaid populations.

Results

Among Medicaid recipients in DERP member states and nationally, minorities are overrepresented (21% to 57%) compared with their presence in the population (10% to 30%). Fifty-nine percent of DERP reviews reported insufficient evidence to evaluate drug effects by race/ethnicity or gender. Three percent of reviews found evidence of differential effects by race and 13% by gender. Twenty-four percent found evidence of no difference by race and 9% found no difference by gender. Most of this evidence was described as weak, limited, or of poor quality. Eighty percent of Medicaid recipients are poor or near-poor. DERP does not report on SES.

Conclusion

DERP reviews reveal deficiencies of the evidence when applied to Medicaid populations. To increase health equity and provide evidence for policies that serve socially disadvantaged populations, drug trials, and other studies should include more members of these populations. Systematic reviews should include low-SES as a prespecified subgroup.

Keywords: Systematic review, Evidence-based medicine, Medicaid, Health equity, Health disparities, Evidence-based health policy