Medical mistrust and COVID-19 vaccine attitudes and behavior: Findings from a population-based cohort study in Michigan.

Background: Uptake of COVID-19 vaccines has stalled in the U.S. Some studies suggest that medical mistrust may be a barrier, but evidence is limited due to cross-sectional designs or convenience sampling.

Methods: We examined associations of medical mistrust with COVID-19 vaccine attitudes at baseline and vaccination uptake at follow-up using a population-based sample of Michigan adults with PCR-confirmed SARS-CoV-2 infection. We summed ratings for three items of the Medical Mistrust Index (MMI) to measure trust in healthcare providers. For vaccine attitudes, we averaged ratings for two items on importance of getting the COVID-19 vaccine. For vaccination uptake as ever receiving at least one dose of a COVID-19 vaccine. We conducted (1) linear regression models to examine cross-sectional associations between MMI and vaccine attitudes (n = 3865), (2) modified Poisson regression with robust standard errors to estimate prospective associations between MMI and vaccination uptake (n = 3741), and (3) effect modification and stratified analyses by race and ethnicity.

Results: The mean MMI score was 1.89. The mean of positive vaccine attitudes measure at baseline was 3.45 and the prevalence of receiving a vaccine at follow-up was 75.3 %. Higher MMI was associated with worse vaccine attitudes at baseline (coefficient = -0.64, 95 % confidence interval [CI]: -0.71, -0.56), and lower vaccine uptake at follow-up (adjusted risk ratio: 0.83, 95 % CI: 0.80, 0.86). Both associations were pronounced among non-Hispanic White and another non-Hispanic race and ethnicity individuals.

Conclusions: Understanding drivers of medical mistrust may help rebuild public trust in healthcare systems to promote vaccine uptake and improve public health.