Background: Inequality is a long-standing public health emergency and recent attention has been placed on diseases that disproportionally affect different genders (i.e. gender refers to observed, experienced, prescribed or favoured social differences based on attributed at birth sex). The relationship between gender inequalities, norms and social determinants of health have resulted in structural barriers in healthcare.
Objectives: A pragmatic literature review was conducted to provide a methodological map of the main issues (biases) related to study planning, design, and data reporting that can exacerbate or hinder understanding of the impact of gender health inequalities in pharmacoepidemiology. Recommendations from topic-related research were summarized, when available.
Methods: Following PRISMA guidelines, literature databases (Embase, MEDLINE) were systematically searched for methodological commentaries, primary research, or review articles published in English since 2012. A snowballing search of references of included publications was done to identify relevant articles. Dual data screening and extraction were conducted by trained reviewers. Results were synthesized qualitatively across included records.
Results: Database searches returned 1,122 records. Seven publications were included after abstract and full-text screening. Two relevant articles were retrieved from other sources. Long-standing issues with inconsistent gender and sex terminology, systematic erroneous defining of gender-related variables and gender insensitivity in literature indexing were found to be methodological barriers to fully measure the impact of gender on health outcomes. Study design protocols should aim to standardize gender-specific variables and the complex interdependency among biological sex, gender as a social construct, and health. Female representation and availability of stratified information in studies, currently not widely covered, and use of causal analysis can avert misleading results. Different types of biases (measurement and selection) should be quantified before incorrectly assuming health outcomes, risks, and economic outcomes among genders are similar/different. Gender research can benefit from the opportunities generated by digital technologies, clinical informatics, and large-scale real-world studies.
Conclusions: Generating evidence-based epidemiological research to explore the origin and impact of gender health inequalities needs to be based on sound methodological principles. There is an opportunity to establish gender-specific guidance for researchers, industry, and decision-makers to ensure gender diversity in data collection, standardized reporting, and analysis.
