Abstract
BACKGROUND: Approximately 4-6% of incident end stage renal disease (ESRD) patients in the U.S. recover enough kidney function to discontinue dialysis but there is considerable geographic variation. We undertook this study to investigate whether state-level variations in renal recovery among incident ESRD patients correlated with state-level variations in incidence of acute kidney injury requiring dialysis (AKI-D). METHODS: We conducted a national cross-sectional ecological study at the state-level using data from State Inpatient Databases and U.S. Renal Data System. All hospital admissions and all ESRD patients in 18 US states (AZ, AR, CA, FL, IA, KY, MA, MD, MI, NJ, NM, NY, NV, OR, RI, SC, VT, and WA) were included. Correlation between AKI-D incidence and rate of renal recovery across states was determined using Pearson's r (overall and in subgroups). We also calculated partial correlations adjusted for sex and age. RESULTS: AKI-D incidence ranged from 99.0 per million population (pmp) in Vermont to 490.4 pmp in Nevada. Rate of renal recovery among incident ESRD patients ranged from 8.8 pmp in Massachusetts to 29.3 pmp in Florida. A positive correlation between AKI-D incidence and rate of renal recovery among incident ESRD patients at state level was found overall (unadjusted r = 0.67; p = 0.002) and in age, sex, and race subgroups. The overall correlation persisted after adjusting for age (adjusted r = 0.62; p < 0.001) and sex (adjusted r = 0.65; p < 0.001). CONCLUSION: Our findings suggest that AKI-D incidence is an important driver of renal recovery rates among incident ESRD patients.