Mortality Rates in Patients with ADPKD Differ by Race

NKF Spring Clinical Meetings 2021

Results of previous studies have suggested racial differences among patients with autosomal dominant polycystic kidney disease (ADPKD) in access to treatment, progression of disease, and mortality. Greg Mader, PhD, and colleagues conducted an analysis of data on ADPKD patients ≥65 years of age to estimate race-specific mortality in patients with CKD stages 1 through 5 and patients with end-stage renal disease (ESRD).

Results of the analysis were reported during a virtual poster session at the NKF Spring Clinical Meetings 2021. The poster was titled Racial Differences in Mortality Rates among Elderly Non-ESRD CKD and ESRD Patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD): Study Findings Using Data from the USRDS.

The analysis included data from the 2014, 2015, or 2016 United States Real Data System (USRDS) non-ESRD CKD cohort (assembled from Medicare claims data 5% sample) with at least two diagnosis codes for ADPKD. CKD stage determination was based on at least two consecutive stage diagnosis codes and age was determined at study entry. Patients with ESRD with at least one code for ADPKD diagnosis and an ESRD service date from January 2, 2104, to December 31, 2016, were also included. Mortality rates were estimated by race, sex, CKD stage, age group, and overall.

A total of 1551 elderly patients with ADPKD and non-ESRD CKD met staging criteria (0.089% of the overall non-ESRD CKD cohort). Mean age was 76.5 years, 54.4% were male, 81.3% were White, 12.5% were Black, 1.5% were Hispanic, 2.1% were Asian, and 2.6% were other or unknown race/ethnicity.

The cohort of elderly patients with ADPKD and ESRD included 14,756 patients (0.460% of the ESRD cohort). Mean age was 70.8 years, 50.4% were male, 77.3% were White, 10.9% were Black, 8.0% were Hispanic, 2.9% were Asian, and 0.8% were other or unknown race/ethnicity.

Following adjustment for age, in the non-ESRD CKD cohort the mortality rate was highest for Black patients. In the ESRD cohort, the age-adjusted morality rate was highest for White patients.

In conclusion, the researchers said, “Our results show racial differences in mortality among elderly ADPKD patients in both non-ESRD CKD and ESRD cohorts and suggest a possible survivorship effect among elderly Black ADPKD patients with ESRD.”

Source: Mader G, Mladsi D, Zhou X, et al. Racial differences in mortality rates among elderly non-ESRD CKD and ESRD patients with autosomal dominant polycystic kidney disease (ADPKD): Study findings using data from the USRDS. Abstract of a poster presented at the National Kidney Foundation virtual Spring Clinical Meetings 2021 (Abstract #312), April 9, 2021.