Objective:Previous pandemics may offer evidence on mediating factors that contributed to disparities in infection and poor outcomes, which could inform the effort to mitigate potential unequal outcomes during the current COVID-19 pandemic. This systematic review sought to examine those factors.Methods:We searched MEDLINE, PsycINFO, and Cochrane to May 2020. We included studies examining health disparities in adult U.S. populations during infectious disease epidemics or pandemics. Two investigators screened abstracts and full text. We assessed study quality using the Newcastle/Ottawa Scale or the Critical Appraisal Skills Programme Checklist for Qualitative Studies.Results:Sixteen articles were included, of which 14 focused on health disparities during the 2009 H1N1 influenza pandemic. Studies showed that disparities during the H1N1 pandemic were more related to differential exposure to the virus than to susceptibility or access to care. Overall, pandemic-related disparities emanate primarily from inequalities in social conditions that place racial and ethnic minorities and low socioeconomic status populations at greater risk of exposure and infection, rather than individual-level factors such as health behaviors and comorbidities.Conclusions:Policy- and systems-level interventions should acknowledge and address these social determinants of heightened risk, and future research should evaluate the effects of such interventions to avoid further exacerbation of health inequities during the current and future pandemics.

Data suggest that the effects of coronavirus disease 2019 (COVID-19) differ among U.S. racial/ethnic groups.To evaluate racial/ethnic disparities in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates and COVID-19 outcomes, factors contributing to disparities, and interventions to reduce them.English-language articles in MEDLINE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus, searched from inception through 31 August 2020. Gray literature sources were searched through 2 November 2020.Observational studies examining SARS-CoV-2 infections, hospitalizations, or deaths by race/ethnicity in U.S. settings.Single-reviewer abstraction confirmed by a second reviewer; independent dual-reviewer assessment of quality and strength of evidence.37 mostly fair-quality cohort and cross-sectional studies, 15 mostly good-quality ecological studies, and data from the Centers for Disease Control and Prevention and APM Research Lab were included. African American/Black and Hispanic populations experience disproportionately higher rates of SARS-CoV-2 infection, hospitalization, and COVID-19-related mortality compared with non-Hispanic White populations, but not higher case-fatality rates (mostly reported as in-hospital mortality) (moderate- to high-strength evidence). Asian populations experience similar outcomes to non-Hispanic White populations (low-strength evidence). Outcomes for other racial/ethnic groups have been insufficiently studied. Health care access and exposure factors may underlie the observed disparities more than susceptibility due to comorbid conditions (low-strength evidence).Selection bias, missing race/ethnicity data, and incomplete outcome assessments in cohort and cross-sectional studies must be considered. In addition, adjustment for key demographic covariates was lacking in ecological studies.African American/Black and Hispanic populations experience disproportionately higher rates of SARS-CoV-2 infection and COVID-19-related mortality but similar rates of case fatality. Differences in health care access and exposure risk may be driving higher infection and mortality rates.Department of Veterans Affairs, Veterans Health Administration, Health Services Research & Development. (PROSPERO: CRD42020187078).

BACKGROUND:Data suggest that there were disparities in H1N1 vaccine uptake, and these may inform COVID-19 vaccination efforts. We conducted a systematic review to evaluate disparities in H1N1 vaccine uptake, factors contributing to disparities, and interventions to reduce them. METHODS:We searched English-language articles in MEDLINE ALL, PsycINFO, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials from database inception through May 8, 2020. Observational studies examining H1N1 vaccine uptake by race/ethnicity, socioeconomic status, rurality, and disability status in US settings were included. Two reviewers independently assessed study eligibility. Single-reviewer data abstraction was confirmed by a second reviewer. We conducted independent dual quality assessment, and collective strength of evidence assessment. RESULTS:We included 21 studies. African American/Black, Latino, and low-socioeconomic status participants had disproportionately lower H1N1 vaccination rates (low- to moderate-strength evidence). However, Latinos were more likely than Whites to intend to be vaccinated, and African American/Blacks and participants with lower-socioeconomic status were just as likely to intend to be vaccinated as their White and higher-socioeconomic status counterparts (low-strength evidence). Vaccine uptake for other groups has been insufficiently studied. Factors potentially contributing to disparities in vaccine uptake included barriers to vaccine access, inadequate information, and concerns about vaccine safety and efficacy. Studies were largely cross-sectional. Many of the studies are a decade old and were conducted in the context of a different pandemic. The categorization of racial and ethnic groups was not consistent across studies and not all groups were well-studied. DISCUSSION:Efforts to avoid disparities in COVID-19 vaccination uptake should prioritize vaccine accessibility and convenience in African American/Black, Latino, and low-SES communities; engage trusted stakeholders to share vaccine information; and address concerns about vaccine safety and efficacy. PRIMARY FUNDING SOURCE:Department of Veterans Affairs, Veterans Health Administration, Health Services Research & Development. PROTOCOL REGISTRATION:PROSPERO CRD42020187078.

BACKGROUND:Data suggest that the effects of coronavirus disease 2019 (COVID-19) differ among U.S. racial/ethnic groups. PURPOSE:To evaluate racial/ethnic disparities in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates and COVID-19 outcomes, factors contributing to disparities, and interventions to reduce them. DATA SOURCES:English-language articles in MEDLINE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus, searched from inception through 31 August 2020. Gray literature sources were searched through 2 November 2020. STUDY SELECTION:Observational studies examining SARS-CoV-2 infections, hospitalizations, or deaths by race/ethnicity in U.S. settings. DATA EXTRACTION:Single-reviewer abstraction confirmed by a second reviewer; independent dual-reviewer assessment of quality and strength of evidence. DATA SYNTHESIS:37 mostly fair-quality cohort and cross-sectional studies, 15 mostly good-quality ecological studies, and data from the Centers for Disease Control and Prevention and APM Research Lab were included. African American/Black and Hispanic populations experience disproportionately higher rates of SARS-CoV-2 infection, hospitalization, and COVID-19-related mortality compared with non-Hispanic White populations, but not higher case-fatality rates (mostly reported as in-hospital mortality) (moderate- to high-strength evidence). Asian populations experience similar outcomes to non-Hispanic White populations (low-strength evidence). Outcomes for other racial/ethnic groups have been insufficiently studied. Health care access and exposure factors may underlie the observed disparities more than susceptibility due to comorbid conditions (low-strength evidence). LIMITATIONS:Selection bias, missing race/ethnicity data, and incomplete outcome assessments in cohort and cross-sectional studies must be considered. In addition, adjustment for key demographic covariates was lacking in ecological studies. CONCLUSION:African American/Black and Hispanic populations experience disproportionately higher rates of SARS-CoV-2 infection and COVID-19-related mortality but similar rates of case fatality. Differences in health care access and exposure risk may be driving higher infection and mortality rates. PRIMARY FUNDING SOURCE:Department of Veterans Affairs, Veterans Health Administration, Health Services Research & Development. (PROSPERO: CRD42020187078).