(1349) Low Vaccination Adherence Rates Identified on a Pharmacist-led Inpatient Transitions of Care Service

Objectives: Approximately 1.5 million people worldwide die annually of vaccine-preventable diseases. In the United States alone, pneumococcal disease contributes to around 5,000 deaths per year and influenza contributes to over 100,000 hospital admissions and 5,000 deaths per season. Although mortality rates for both tetanus and COVID-19 are declining, the highest rates of mortality occur in high-risk patients over 55 years old. The transitions of care consult service at Temple University Hospital (TUH) focuses on complex patients who are candidates for multiple vaccines prompting us to evaluate vaccination history. The primary objective of the study is to identify patient nonadherence to select indicated vaccines. A secondary objective is to determine if there is an association with vaccination status and social determinants of health.

Methods: This was a retrospective cohort study of adult patients admitted to TUH who received a pharmacy transitions of care consult from May 2021-May 2022. Patients were assessed for indications to receive pneumococcal (PNA), Tdap or Td, COVID-19, influenza, and zoster vaccines as per the CDC Adult Immunization Schedule and availability of the seasonal influenza vaccine. The Pennsylvania Statewide Immunization Information System (PA-SIIS) vaccine registry and provider documentation from electronic health records (EHR) were used to evaluate vaccination status. Patients who were not vaccinated as per the CDC recommendations were labeled as nonadherent. Social determinants of health including employment status, preferred language, place of residence or homelessness, insurance status, and establishment with a primary care provider were collected from the EHR.
Categorical data were reported as frequency and percentage, analyzed using either a 2-proportions or Fisher’s Exact test. Continuous data were reported as mean and standard deviation or median and interquartile range based on normality of distribution. Parametric data was analyzed using a 2 sample T-test and nonparametric data using a Mann Whitney U test.

Results: Included in the analysis were 225 patients of which 213 (94.7%) were nonadherent, missing at least one indicated vaccine. Baseline demographics that were significantly different between the groups include number of Asian patients (0% vs. 11%; p=0.040) and patients with COPD (26.3% vs 0%; p=0.041), in the nonadherent and up-to-date groups respectively. Compared to the up-to-date group, the nonadherent group had more males (50.7% vs 41.6%), African American patients (63.4% vs 50.0%), and were older (60.7±14.5 vs. 54.3±12.5). Nonadherence was highest with the zoster vaccine, at a rate of 92.0%, followed by influenza vaccination at 66.2%.
The social determinants of health were similar between groups. Although not statistically significant, a larger proportion of nonadherent patients were unemployed (49.8% vs 33.3%), preferred a language other than English (11.7% vs 8.3%) and had Medicaid or Medicare insurance (90.1% vs 83.3%), while the up-to-date group has a larger proportion of patients with private insurance (16.7% vs. 3.3%).

Conclusions: Of the vaccines included in this review, we identified high rates of nonadherence to recommended vaccines, with zoster being the highest. Significantly more patients with COPD were nonadherent to receiving indicated vaccines than those without.

There are a few limitations in our study design. This was a retrospective analysis of subjects from one institution, where vaccination documentation from outside providers and pharmacies may be missed. We limited missing information by referencing PA-SIIS and documentation in the medical record, but vaccinations received out of state would not be included.

The results of this study highlight the need for inpatient review of vaccination history. An inpatient pharmacist workflow that incorporates review of vaccine history and social determinants of health may better identify at-risk patients for vaccine-preventable diseases and increase vaccination rates.