Abstract: TH-PO0651
Effect of Truncating the GFR Slope on Its Association with Kidney Failure
Session Information
- CKD: Clinical - Guidelines, Biomarkers, Progression, Procedures, Outcomes, and More
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2202 CKD (Non-Dialysis): Clinical, Outcomes, and Trials
Author
- Teali, Ishfaq Rashid, Tufts Medical Center, Boston, Massachusetts, United States
Group or Team Name
- Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Clinical Trials Consortium
Background
GFR slope is a valid surrogate endpoint for kidney failure in CKD randomized controlled trials (RCTs). Current trials have shorter follow-up than past trials, which may limit use of GFR slopes. We evaluated the association of the treatment effects on GFR slope and on a composite kidney clinical endpoint after truncating follow-up to 18 or 24 months.
Methods
In an individual participant analysis, we used Bayesian mixed-effects meta-regression to assess associations between treatment effects on chronic, 2- and 3-year GFR slopes and on a composite clinical endpoint (treated kidney failure, doubling of serum creatinine, or eGFR <15 mL/min/1.73 m2). Slopes were estimated using full follow-up and datasets truncated at 24 (t24) and 18 months (t18) in eligible trials. In subgroup analysis, we examined whether results were consistent by median follow-up < or ≥3 years.
Results
Among 49 trials (125,628 participants) with sufficient observations for t24 analysis, mean follow-up decreased from 40.4 to 10.1 months, and among the 44 trials (106,357 participants) with sufficient observations for t18 analysis, mean follow-up decreased from 39.4 to 7.8 months. For both t24 and t18, minimal differences were observed for GFR slopes in both treatment arms as well as treatment effects on GFR slopes. Standard errors of the GFR slope and treatment effects also had minimal differences, with few outliers. Associations between treatment effects on GFR slopes and on the clinical endpoints were consistent between full and truncated follow-ups [Table 1]. Results were consistent across subgroups (<3 vs ≥3 years), with slightly greater variability in shorter-follow-up trials.
Conclusion
Truncating follow-up to 24 or 18 months did not materially change trial-level associations between GFR slope and clinical outcomes, supporting GFR slope evaluated over shorter follow-up as a robust surrogate in shorter CKD trials.
Acknowledgment
We thank the CKD-EPI Clinical Trials Consortium, the National Kidney Foundation (NKF), the Utah study team, and AstraZeneca for their contributions to data sharing and collaborative research efforts that supported this work.
Trial-level analysis for chronic, 2-y, 3-y total GFR slope vs. standard clinical endpoint across different follow-up windows.
Funding
- Commercial Support – AstraZeneca