From admission to vaccination: COVID-19 vaccination patterns and their relationship with hospitalization in trauma patients

Background: COVID-19 vaccination rates in the hospitalized trauma population are not fully characterized and may lag behind the general population. This study aimed to outline COVID-19 vaccination trends in hospitalized trauma patients and examine how hospitalization influences COVID-19 vaccination rates. Methods: We conducted a retrospective institutional study using our trauma registry paired with the COVID-19 vaccination ENCLAVE registry. We included patients >18 years admitted between April 21, 2021 and November 30, 2022. Our primary outcome was the change in vaccination posthospitalization, and secondary analyzed outcomes included temporal trends of vaccination in trauma patients and predictors of non-vaccination. We compared pre and posthospitalization weekly vaccination rates. We performed joinpoint regression to depict temporal trends and multivariate regression for predictors of nonvaccination. Results: The rate of administration of the first vaccine dose increased in the week after hospitalization (P = .018); however, this increase was not sustained in the following weeks. The percentage of unvaccinated patients declined faster in the general population in Massachusetts compared to the hospitalized trauma population. By the conclusion of the study, 27.1% of the trauma population was unvaccinated, whereas <5% of the Massachusetts population was unvaccinated. Urban residence, having multiple hospitalizations, and experiencing moderate to severe frailty were associated with vaccination. Conversely, being in the age groups 18 to 45 years and 46 to 64 years, as well as having Medicaid or self- pay insurance, were linked to being unvaccinated. Conclusion: Hospitalization initially increased the rate of administration of the first vaccine dose in trauma patients, but the effect was not sustained. By the conclusion of the study period, a greater percentage of trauma patients were unvaccinated compared to the general population of Massachusetts. Strategies for sustained health care integration need to be developed to address this ongoing challenge in the high-risk trauma population.