Disparities in Vaccination Amongst Socially Vulnerable Patients with Inflammatory Bowel Disease

Abstract

Introduction: Social determinants of health (SDOH) have a known impact on disparities in vaccination. Despite an increased risk for infection in patients with inflammatory bowel disease (IBD), SDOH and vaccination in this population have not been studied. Using census tract-level data from the Centers for Disease Control's social vulnerability index (SVI), we aimed to understand the relationship between SDOH and adherence to guideline-recommended vaccinations in patients with IBD.

Methods: A single-center retrospective cohort of patients with IBD was used to geocode patient addresses to their individual census tract and corresponding SVI and subthemes (Socioeconomic Status, Household Composition, Minority Status, and Housing/Transportation). We used separate multivariable logistic regressions to examine the relationship between SVI and vaccination against influenza, COVID-19, pneumococcal pneumonia, and herpes zoster.

Results: A total of 7,036 patients were included. Rates of vaccination varied across vaccine-types: influenza (57%), COVID-19 (65%), pneumococcal pneumonia (58%), and herpes zoster (11%). High social vulnerability was associated with lower odds of vaccination against influenza (OR 0.47, p < 0.001), COVID-19 (OR 0.54, p < 0.001), pneumonia (OR 0.73, p = 0.012), and herpes zoster (OR 0.39, p < 0.001). Within the SVI subthemes, Socioeconomic Status, Household Composition, and Minority Status were important factors associated with differences in vaccine uptake.

Conclusion: Higher social vulnerability was associated with lower rates of vaccination across all vaccine types. Identifying these disparities in vaccination for socially vulnerable patients with IBD is the first step to reducing preventable infections and ensuring all patients receive high quality, equitable care.

Keywords: Crohn’s disease; Health equity; Preventive care; Ulcerative colitis.

Figure 1.

Patient Flow Diagram By Vaccine Cohort ¹Influenza vaccination defined as having received any flu vaccine from 9/1/2019-3/1/2020 ^a Patients who were lost to follow-up before 9/1/2019 or who established care after 3/1/2020 were excluded ² COVID-19 vaccination defined as having received at least 2 vaccinations against SARS-CoV-2 ^b Patients who were lost to follow-up before 4/1/2021 were excluded. Patients with less than 1 month of data were also excluded. ³ Pneumococcal vaccination defined as having received one pneumococcal polysaccharide vaccine ^c Patients who were not immunocompromised, active smokers, or 65 years or older were excluded ^d Patients who established care after 3/1/2020 were excluded. ⁴ Herpes zoster vaccination defined as having received both recombinant vaccines ^e Patients who established care after 3/1/2020 were excluded. Patients with less than 6 months of data were also excluded.

Figure 2.

Rates of Vaccination Among Patients With and Without an Established Gastroenterologist A “GI patient” was defined as a patient who had seen a gastroenterologist in clinic at the University of Michigan during the study period. A “non-GI patient” was defined as a patient who had not seen a gastroenterologist at the University of Michigan during the study period.