Racial Disparity in Hospitalization Rate among Patients on Dialysis

Results of previous studies have demonstrated an association between community racial composition and mortality in patients with end-stage renal disease (ESRD). There are few data available on whether there is an association between living in communities with predominantly Black residents and risk for hospitalization among patients on hemodialysis. Ladan Golestaneh MD, MS, and colleagues conducted a retrospective analysis of prospectively collected data from a cohort of patients on hemodialysis.

The data included 4567 patients who were treated in 154 dialysis facilities in 127 unique zip codes; the patients were participants in US-DOPPS (United States Dialysis Outcomes and Practice Patterns Study), phases 4-5 (2019-2015). The analysis outcome of interest was the rate of hospitalizations during the study period. Analysis results were reported online in the American Journal of Kidney Diseases [doi.org/10.1053/j.ajkd.2020.05.019].

The researchers stratified participants into tertiles of percent of Black residents with patients’ dialysis facility’s zip code via a link to the American Community Survey: tertile 1, ≤1.8% (median 1%) Black residents; tertile 3, ≥14.4% (median, 34.2%) Black residents.

Associations between patient-, facility-, and community-level variables and percent Black residents were examined using ANOVA [analysis of variance], Kruskal Wallis, or Chi-square/Fisher exact tests. The incidence rate ratio (IRR) for hospitalizations between the communities was estimated using negative binomial regression, with and without adjustment for potential confounding variables.

Mean age of the study cohort was 62.7 years; 53% were white, 27% were Black, and 45% were female. Patients receiving dialysis in facility zip codes with a higher (tertile 3) versus lower (tertile 1) percentage of Black residents were more likely to be younger, Black, live in urban environments with lower socio-economic status, have a catheter as a vascular access, and have fewer comorbidities. Patients receiving dialysis in communities with the highest tertile of Black residents had a higher adjusted rate of hospitalization (adjusted IRR, 1.32; 95% confidence interval, 1.12-1.56), compared with communities within the lowest tertile.

The authors cited potential residual confounding as a limitation to the analysis results.

In conclusion, the researchers said, “The risk of hospitalization for patients with ESRD is higher among those treated in communities with a higher percentage of Black residents after adjustment for dialysis care as well as patient demographics and comorbidities. Understanding the cause of this association should be a priority of future investigation.”