Factors Associated With Non-vaccination for Influenza Among Patients With CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

Abstract

Rationale & objective: Vaccination for influenza is strongly recommended for people with chronic kidney disease (CKD) due to their immunocompromised state. Identifying risk factors for not receiving an influenza vaccine (non-vaccination) could inform strategies for improving vaccine uptake in this high-risk population.

Study design: Longitudinal observational study.

Setting & participants: 3,692 Chronic Renal Insufficiency Cohort Study (CRIC) participants.

Exposure: Demographic factors, social determinants of health, clinical conditions, and health behaviors.

Outcome: Influenza non-vaccination, which was assessed based on a receipt of influenza vaccine ascertained during annual clinic visits in a subset of participants who were under nephrology care.

Analytical approach: Mixed-effects Poisson models to estimate adjusted prevalence ratios (APRs).

Results: Between 2009 and 2020, the pooled mean vaccine uptake was 72% (mean age, 66 years; 44% female; 44% Black race). In multivariable models, factors significantly associated with influenza non-vaccination were younger age (APR, 2.16 [95% CI, 1.85-2.52] for<50 vs≥75 years), Black race (APR, 1.58 [95% CI, 1.43-1.75] vs White race), lower education (APR, 1.20 [95% CI, 1.04-1.39 for less than high school vs college graduate]), lower annual household income (APR, 1.26 [95% CI, 1.06-1.49] for <$20,000 vs >$100,000), formerly married status (APR, 1.22 [95% CI, 1.09-1.35] vs currently married), and nonemployed status (APR, 1.13 [95% CI, 1.02-1.24] vs employed). In contrast, participants with diabetes (APR, 0.80 [95% CI, 0.73-0.87] vs no diabetes), chronic obstructive pulmonary disease (COPD) (APR, 0.80 [95% CI, 0.70-0.92] vs no COPD), end-stage kidney disease (APR, 0.64 [0.56 to 0.76] vs estimated glomerular filtration rate≥60mL/min/1.73m²), frailty (APR, 0.86 [95% CI, 0.74-0.99] vs no frailty), and ideal physical activity (APR, 0.90 [95% CI, 0.82-0.99] vs. physically inactive) were less likely to have non-vaccination status.

Limitations: Possible residual confounding.

Conclusions: Among adults with CKD receiving nephrology care, younger adults, Black individuals, and those with adverse social determinants of health were more likely to have the influenza non-vaccination status. Strategies are needed to address these disparities and reduce barriers to vaccination.

Plain-language summary: Identifying risk factors for not receiving an influenza vaccine ("non-vaccination") in people living with kidney disease, who are at risk of influenza and its complications, could inform strategies for improving vaccine uptake. In this study, we examined whether demographic factors, social determinants of health, and clinical conditions were linked to the status of not receiving an influenza vaccine among people living with kidney disease and receiving nephrology care. We found that younger adults, Black individuals, and those with adverse social determinants of health were more likely to not receive the influenza vaccine. These findings suggest the need for strategies to address these disparities and reduce barriers to vaccination in people living with kidney disease.

Keywords: Chronic kidney disease; infectious disease; influenza; vaccination.

Figure 1:

Proportion of participants receiving influenza vaccine by year

Figure 2:. Factors significantly associated with influenza non-vaccination. A: Demographic factors and social determinants of health. B: Clinical conditions and health behaviors

Due to the number of characteristics examined in the analysis, the figure presents only those showed significant associations. A 2-sided p-value of <0.05 compared to the reference group was considered statistically significant. Global tests were not significant for the categories of household income and physical activity and therefore the statistical evidence for these categories may not be as strong as other factors. Other factors that did not show a significant association were presented in Table S3. Excluding an exposure of interest (e.g., age), models were adjusted for age, sex, race, center, enrollment phase, diabetes, hypertension, history of CVD, COPD, cancer, eGFR category, and UPCR category.

Figure 2:. Factors significantly associated with influenza non-vaccination. A: Demographic factors and social determinants of health. B: Clinical conditions and health behaviors

Due to the number of characteristics examined in the analysis, the figure presents only those showed significant associations. A 2-sided p-value of <0.05 compared to the reference group was considered statistically significant. Global tests were not significant for the categories of household income and physical activity and therefore the statistical evidence for these categories may not be as strong as other factors. Other factors that did not show a significant association were presented in Table S3. Excluding an exposure of interest (e.g., age), models were adjusted for age, sex, race, center, enrollment phase, diabetes, hypertension, history of CVD, COPD, cancer, eGFR category, and UPCR category.

Figure 3:. Histograms for the frequency of receiving an influenza vaccine

The probability of receiving an influenza vaccine was calculated as the number of years a participant answered yes to receiving an influenza vaccine divided by the number of years a participant responded to the question regarding influenza vaccination. Receiving an influenza vaccine less than 50% (orange or yellow) was considered infrequent influenza vaccination as indicated in the bracket.

Figure 4:. Factors significantly associated with infrequent influenza vaccination. A: Demographic factors and social determinants of health. B: Clinical conditions and health behaviors

Excluding an exposure of interest (e.g., age), models were adjusted for age, sex, race, center, enrollment phase, diabetes, hypertension, history of CVD, COPD, cancer, eGFR category, and UPCR category. A 2-sided p-value of <0.05 compared to the reference group was considered statistically significant. Other factors that did not show a significant association were shown in Table S3.

Figure 4:. Factors significantly associated with infrequent influenza vaccination. A: Demographic factors and social determinants of health. B: Clinical conditions and health behaviors

Excluding an exposure of interest (e.g., age), models were adjusted for age, sex, race, center, enrollment phase, diabetes, hypertension, history of CVD, COPD, cancer, eGFR category, and UPCR category. A 2-sided p-value of <0.05 compared to the reference group was considered statistically significant. Other factors that did not show a significant association were shown in Table S3.