Equity considerations in COVID-19 vaccination studies of individuals with autoimmune inflammatory rheumatic diseases

Objective: We sought to examine the extent to which populations experiencing inequities were considered in studies of COVID-19 vaccination in individuals with autoimmune inflammatory rheumatic diseases (AIRDs). Methods: We included all studies (N=19) from an ongoing Cochrane living systematic review on COVID-19 vaccination in people with AIRDs. We used the PROGRESS-Plus framework standing for Place of residence, Race/ethnicity, Occupation, Gender/sex, Religion, Education, Socioeconomic status, and Social capital, Plus: age, multimorbidity, and health literacy, to identify factors that stratify health outcomes. We assessed equity considerations in relation to differences in COVID-19 baseline risk, eligibility criteria, description of participant characteristics and attrition, controlling for confounding factors, subgroup analyses, and applicability of findings. Results: All nineteen studies were cohort studies that followed individuals with AIRDs after vaccination. Three studies (16%) described differences in baseline risk for COVID-19 across age. Two studies (11%) defined eligibility criteria based on occupation and age. All nineteen studies described participant age and sex. Twelve studies (67%) controlled for age and/or sex as confounders. Eight studies (47%) conducted subgroup analyses across at least one PROGRESS-Plus factor, most commonly age. Ten studies (53%) interpreted applicability in relation to at least one PROGRESS-Plus factor, most commonly age (47%), then ethnicity (16%), sex (16%), and multimorbidity (11%). Conclusion: Sex and age were the most frequently considered PROGRESS-Plus factors in studies of COVID-19 vaccination in individuals with AIRDs. The generalizability of evidence to populations experiencing inequities is uncertain. Future COVID-19 vaccine studies should report participant characteristics in more detail to inform guideline recommendations.