Uptake and Factors Associated with COVID-19 Vaccination Among 3,779,733 Adults Living With and Without Diabetes: A Population Cohort Study in a Universal Health Care Setting.

Abstract

Objective: People with diabetes are vulnerable to health inequities and population level COVID-19 vaccine uptake among adults with diabetes is unknown. Our aim was to assess COVID-19 vaccine uptake among adults with and without diabetes and the factors associated with vaccination.

Methods: This retrospective, population-based cohort study included all adults living in Alberta, Canada on December 14, 2020, the date COVID-19 vaccines became available. Individual diabetes status was determined between April 1, 2002, and December 14, 2020, using a validated algorithm. Individuals were followed until March 31, 2022. The primary outcome was full vaccination as defined by the manufacturer. Descriptive statistics were used to compare vaccination status among people with and without diabetes. Unadjusted and multivariable-adjusted Cox proportional hazards models were applied to assess factors associated with full vaccination uptake.

Results: Among 3,779,733 adults (49.7% female, mean age 45.1 ± 17.3 years), 9.8% had diabetes. A higher proportion of people with diabetes, compared to those without, were fully vaccinated (83.9% vs. 74.6%, p<0.001; males aHR 1.34, 95% CI 1.33-1.35; females aHR 1.23, 95% CI 1.22-1.24). In people with diabetes, age over 65 years and statin use were associated with full vaccination, whereas lower socioeconomic status, rural residence, higher number of comorbidities, higher A1C, and insulin use were associated with lower vaccination uptake.

Conclusions: People with diabetes had high COVID-19 vaccination uptake. Further work is needed to better understand the system and individual based facilitators of and barriers to, vaccine uptake, to inform future public health vaccine-based interventions.