The Association Between Patient Sociodemographic Characteristics and Generic Drug Use: A Systematic Review and Meta-analysis

BACKGROUND: Generic drugs are bioequivalent and cost-effective alternatives to brand drugs. In 2014, $254 billion was saved because of the use of generic drugs in the United States. OBJECTIVE: To critically assess evidence on the association between patient characteristics and generic drug use in order to inform the development of educational outreach for improving generic drug use among patients. METHODS: We systematically searched the literature between January 2005 and December 2016 using PubMed, Web of Science, Ovid MEDLINE, Google Scholar, and EBSCO IPA-MEDLINE for potentially relevant studies. The titles and abstracts of identified articles were assessed independently by 2 reviewers. Titles and abstracts that were not written in English, were published before 2005, were not empirical, did not contain sociodemographic data, or were not policy or methodologically relevant to generic drug use were excluded. Data were pooled in a meta-analysis using the RStudio software to assess the association of patient-related factors with generic drug use. RESULTS: Our searches resulted in 11 articles on patient-level factors, and 6 of these articles had sufficient information to conduct meta-analyses in the domains of patients’ gender, age, race/ethnicity, and income. Quantitative analysis indicated that no differences in generic drug use existed between subgroups of patients defined by gender, age, or race/ethnicity. However, patients with lower income (i.e., < 200% federal poverty level [FPL]) were more likely to use generic drugs than those with higher income (≥ 200% FPL; pooled OR = 1.32, 95% CI = 1.15-1.52). Heterogeneity was high (I(2) > 75%) for all analyses but income. CONCLUSIONS: Patients with lower income were more likely to use generic drugs, whereas evidence was heterogeneous regarding an association between generic drug use and gender, age, or race/ethnicity. Educational outreach targeting patients with higher incomes to understand their perspectives in generic drugs may help improve generic drug use within that population.