Kidney Week

Abstract: FR-PO0288

Assessing CKD of Unknown Etiology (CKDu) Using a Computable Phenotype at a Quaternary Academic Medical Center in Florida

Session Information

• CKD: Omics, Systemic Stressors, and Targeted Pharmacotherapy
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2201 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Beatty, Norman L., University of Florida College of Medicine, Gainesville, Florida, United States

Norman L. Beatty, MD

• Guo, Yi, Department of Health Outcomes and Biomedical Informatics, University of Florida College of Medicine, Gainesville, Florida, United States

Yi Guo, PhD

• Qin, Xiao, Department of Health Outcomes and Biomedical Informatics, University of Florida College of Medicine, Gainesville, Florida, United States

Xiao Qin, MS

• Vargas Alvarez, Lara M., University of Florida College of Medicine, Gainesville, Florida, United States

Lara M. Vargas Alvarez, MS

• Weinbrenner, Donny, Department of Health Outcomes and Biomedical Informatics, University of Florida College of Medicine, Gainesville, Florida, United States

Donny Weinbrenner

• Diaz, John Michael, Department of Agricultural Education and Communication, University of Florida Institute of Food and Agricultural Sciences, Gainesville, Florida, United States

John Michael Diaz, PhD

Group or Team Name

• Florida CKDu Project

Background

Chronic kidney disease of unknown etiology (CKDu) is growing in awareness among several regions of the world, most notably within agricultural communities located in the tropics. CKDu is characterized by progressive renal dysfunction in the absence of known CKD risk factors with potential epidemiological linkage among occupational health threats including heat stress, heavy metals and agrochemical exposures. Florida’s climate and substantial farming population mirror the environmental and occupational conditions associated with CKDu in endemic regions, yet research in the state remains uncharacterized.

Methods

The University of Florida (UF) Health is a quaternary health care system providing care for residents throughout the state. To explore the presence of CKDu within our network we developed a computable phenotype (CP) that distinguishes CKDu from traditional CKD with a rigorous inclusion and exclusion criterion. The CP excluded CKD patients with known data supporting primary kidney diseases, secondary systemic conditions associated with the development of CKD and other variables such as chronic use of nephrotoxic medications. We extracted de-identified data from unique patients with CKD (n=224,847) within our electronic health records between June 1, 2011, until October 1, 2023.

Results

Our CP uncovered 4,652 CKD patients having CKDu with an overall prevalence 2.06%. Validation of the CP through a randomized protocol with structured chart review demonstrated a sensitivity of 95.8%, specificity of 92.3% and overall accuracy of 96% for our CP to identify CKDu. Applying the 2024 KDIGO estimated glomerular filtration rate (eGFR) categories (G) to this CKDu cohort revealed n=1,201 (25.81%) with G1, n=3,039 (65.32%) with G2, n=232 (5.0%) with G3a, n=42 (0.91%) with G3b, n=12 (0.03%) with G4, n=6 (0.02%) with G5, and n=120 (2.57%) missing eGFR data for staging.

Conclusion

Our findings reveal that CKDu is present within the state of Florida. Further research is underway to identify possible geographical hot spots with a goal to establish a replicable surveillance model for CKDu in our state.

Funding

• Other U.S. Government Support