CKD Prevalence Among Patients With and Without Type 2 Diabetes: Regional Differences in the United States

RATIONALE & OBJECTIVE: Regional variation in chronic kidney disease (CKD) prevalence in patients with or without type 2 diabetes mellitus (T2DM) has not been well characterized. STUDY DESIGN: Spatial and temporal comparative analysis. SETTING & PARTICIPANTS: MarketScan databases were used to identify patients with CKD overall and subgroups of patients with CKD with and without T2DM in the United States. OUTCOMES: Spatial patterns in CKD prevalence based on year, regional clusters of CKD between years, and characteristics of patients in high-prevalence states. ANALYTICAL APPROACH: Geomapping was used to visualize the state-level data of CKD prevalence generated from 2013 to 2018. We used univariate local indicators of spatial association (LISA) to evaluate geographic differences in prevalence, differential LISA for changes in CKD prevalence over time, and the χ(2) test to identify patient characteristics in the top-20th percentile states for the prevalence of CKD. RESULTS: In univariate LISA, low-low clusters, in which a state has a low CKD prevalence and the surrounding states have a below-average CKD prevalence, were observed in the northwest region throughout the study period, regardless of the T2DM status, indicating a consistently low prevalence of CKD clustered in these areas. High-high clusters were observed, regardless of the T2DM status, in the southeast region in more recent years, suggesting an increased CKD prevalence in this region. LIMITATIONS: Health care insurance enrollment might not have been representative of the United States; the estimates were based on claims data that likely underestimated the true prevalence. CONCLUSIONS: Geographic disparities in CKD prevalence appear increasingly magnified, with an increase in the southeastern region of the United States. This increase is especially problematic because patients with CKD in high-prevalence states experience a greater likelihood of chronic conditions than those in the rest of the United States.