Influenza Vaccination Status Reveals Disparities Among Individuals with Kidney Disease

A recent study aimed to assess risk factors for individuals that did not receive the flu vaccine that are living with kidney disease and are at high risk of influenza and associated conditions. Published in the American Journal of Kidney Diseases, researchers identified a connection between demographic factors, social determinants of health, and clinical conditions that led to not receiving an annual flu vaccine.¹

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The study authors noted that immunization for influenza is encouraged for individuals that have been diagnosed with chronic kidney disease (CKD) because the condition weakens the immune system.²

The researchers created the Chronic Renal Insufficient Cohort (CRIC) study which was a longitudinal observational analysis from 2003 to 2008 and 2013 to 2018 that included 3692 individuals with mild to moderate CKD in the United States. The study authors noted that they used receipt of vaccination for influenza during annual clinic visits within the subset of individuals that underwent nephrology care. This allowed the researchers to evaluate the possible factors that could impact vaccination status.²

Using a multivariable mixed effects poisson regression model, the researchers aimed to estimate the prevalence ratio (PR) connected to each characteristic of vaccination status.²

“In this analysis, characteristics could change over time when they were assessed at multiple visits. Multivariable models were adjusted for a subset of exposures specified a priori, including age, sex, race, center, enrollment phase, hypertension, diabetes, history of CVD, COPD, cancer, eGFR, and UPCR. Thus, PRs for these variables were derived from the single model, and when these variables were explored as an exposure of interest, they were excluded from the covariates,” said the study authors in a press release.

The primary outcome of the study was not receiving an influenza vaccine at each annual visit, compared to the secondary outcome that was receiving the influenza vaccine in fewer than 50% of years with assessable vaccination records.

The study authors found that the pooled mean of influenza vaccination uptake between 2009 to 2020 was 72%.¹ Notably, only 44% of individuals consistently received the influenza vaccine annually.²

The researchers compared the unvaccinated and vaccinated groups and found that vaccinated individuals were more likely to be older, White, diabetic, and diagnosed with COPD, cancer, or end-stage kidney disease. They were also reported to have a higher education and household income and be currently married. Individuals that were unvaccinated were more likely to be younger in age, Black, have less educational attainment, lower annual household income, formerly married, and unemployed.

However, the study authors noted that other characteristics like sex, UPCR, functional health literacy, SF-12 score, and the status of smoking and drinking were similar between both groups.²

The findings conducted in this study confirm that improvements must be made to increase vaccination uptake among individuals with CKD. To work on these improvements, targeting individuals with barriers to receive the vaccine and using the role of nephrology care to promote vaccination could be beneficial.¹

“Importantly, nephrology care may represent an important opportunity to increase vaccine uptake in patients with CKD by leveraging trusted relationships between nephrologists and patients. Additionally, involving patient-level stakeholders (e.g., family members, caregivers) may help reduce barriers and provide social support and accountability for preventive health care,” said press release authors.

References

1. Disparities in flu vaccine uptake persist in people with kidney disease. EurekAlert!. News release. September 18, 2023. Accessed November 3, 2023. https://www.eurekalert.org/news-releases/1001892.
2. Factors Associated With Non-vaccination for Influenza Among Patients With CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study. American Journal of Kidney Diseases. News release. September 15, 2023. Accessed November 3, 2023. https://www.ajkd.org/article/S0272-6386(23)00799-0/fulltext.