Glomerular filtration rate (GFR)-based end points, either as time-to-event end points or as mean rate of decline in GFR (slope), are possible end points in randomized controlled trials (RCTs) evaluating treatments for the progression of chronic kidney disease. We have previously demonstrated robust trial-level associations between treatment effects on GFR decline and treatment effects on the clinical end point of kidney failure with replacement therapy (KFRT).1,2 Treatment effects on GFR decline are increasingly adopted for use in RCTs.