In the United States, 18.9% of the variation in death rates among patients with end-stage kidney disease (ESKD) is attributable to county-level factors such as demographics and health care spending, according to investigators.
Using 2010-2018 data from the United States Renal Data System, investigators identified 1,515,986 adults (aged 18-84 years) who initiated renal replacement therapy from 2781 US counties.
All-cause mortality rates (ASMR) standardized by age among patients with ESKD ranged from 45 to 1022 per 1000 person-years across counties, Kylie K. Snow, MPH, of Rollins School of Public Health, Emory University, Atlanta, Georgia, and colleagues reported in Kidney360. ASMRs were highest in counties located in the Tennessee Valley and Appalachia regions, and lowest in counties located in New England, the Pacific Northwest, and southern California. State-level ASMRs ranged from -8.8 per 1000 person-years in Minnesota to 27.9 per 1000 person-years in North Dakota, but were less telling.
County characteristics — demographic, socioeconomic, health care, and health behavior factors — explained 18.9% of the variation in ESKD mortality. In fully adjusted models, the highest ESKD-related mortality was found in counties with a lower percentage of Black residents (-4.94 per 1000 person-years per county), lower kidney transplant rate (-4.08 per 1000 person-years per county), but higher average Medicare spending per enrollee (5.21 per 1000 person-years per county).
ESKD develops in Black patients at younger ages indicating survival bias, according to investigators. Black patients also tend to have higher body mass index, which may result in an obesity paradox. The investigators also pointed out that access to transplants appears to be a more important factor in ESKD mortality than quality of care. Higher Medicare expenditure may simply reflect a higher disease burden. Regions of high ESKD mortality tended to have higher rates of ESKD risk factors, such as diabetes, chronic kidney disease (CKD), and hypertension, as well as other chronic diseases such as cardiovascular disease.
The investigators wrote that “interventions to reduce ESKD mortality could be targeted to counties with high ESKD mortality. Such interventions should combine knowledge from a growing evidence base on the individual and county-level factors associated with ESKD mortality and its upstream causes.”
Snow K, Patzer R, Patel S, Harding J. County-level characteristics associated with variation in end-stage kidney disease mortality in the United States, 2010-2018. Kidney360. Published online March 3, 2022. doi:10.34067/KID.0007872021