Exploring reasons for state-level variation in incidence of dialysis-requiring acute kidney injury (AKI-D) in the United States
Authors: Chen Zijin , McCulloch Charles E. , Powe Neil R. , Heung Michael , Saran Rajiv , Pavkov Meda E. , Burrows Nilka Rios , Hsu Raymond K. , Hsu Chi-yuan ,   for the Centers for Disease Control and Prevention Chronic Kidney Disease Surveillance Team Neil Powe, Banerjee Tanushree , Tuot Delphine , Hsu Chi-yuan , McCulloch Charles , Crews Deidra , Hsu Raymond , Grubbs Vanessa , Bibbins-Domingo Kirsten , Saran Rajiv , Modi Zubin , Gipson Debbie , Shahinian Vahakn , Gillespie Brenda , Morgenstern Hal , Heung Michael , Herman William , Bragg-Gresham Jennifer , Stack Austin , Balkrishnan Rajesh , Yee Jerry , Steffick Diane , Zhang Xiaosong , Xiang Jie , Han Yun , Yin Maggie , Zivin Kara , Ginier Emily , Kurtz Vivian , Wyncott April , Burrows Nilka Ríos , Eberhardt Mark , Everhart La Shaundra , Mondesire Juanita , Patel Priti , Pavkov Meda , Rolka Deborah , Waller Sharon Saydah Larry 
Published: August 2020

Abstract
Background
There is considerable state-level variation in the incidence of dialysis-requiring acute kidney injury (AKI-D). However, little is known about reasons for this geographic variation.

Methods
National cross-sectional state-level ecological study based on State Inpatient Databases (SID) and the Behavioral Risk Factor Surveillance System (BRFSS) in 2011. We analyzed 18 states and six chronic health conditions (diabetes mellitus [diabetes], hypertension, chronic kidney disease [CKD], arteriosclerotic heart disease [ASHD], cancer (excluding skin cancer), and chronic obstructive pulmonary disease [COPD]). Associations between each of the chronic health conditions and AKI-D incidence was assessed using Pearson correlation and multiple regression adjusting for mean age, the proportion of males, and the proportion of non-Hispanic whites in each state.

Results
The state-level AKI-D incidence ranged from 190 to 1139 per million population. State-level differences in rates of hospitalization with chronic health conditions (mostly < 3-fold difference in range) were larger than the state-level differences in prevalence for each chronic health condition (mostly < 2.5-fold difference in range). A significant correlation was shown between AKI-D incidence and prevalence of diabetes, ASHD, and COPD, as well as between AKI-D incidence and rate of hospitalization with hypertension. In regression models, after adjusting for age, sex, and race, AKI-D incidence was associated with prevalence of and rates of hospitalization with five chronic health conditions--diabetes, hypertension, CKD, ASHD and COPD--and rates of hospitalization with cancer.

Conclusions
Results from this ecological analysis suggest that state-level variation in AKI-D incidence may be influenced by state-level variations in prevalence of and rates of hospitalization with several chronic health conditions. For most of the explored chronic conditions, AKI-D correlated stronger with rates of hospitalizations with the health conditions rather than with their prevalences, suggesting that better disease management strategies that prevent hospitalizations may translate into lower incidence of AKI-D.