Optimizing Sample Size Calculation for Early-Stage CKD Trials Using eGFR Slope

The authors aimed to derive a sample size formula for early-stage chronic kidney disease (CKD) trials that accounts for various design parameters, including slope difference, trial duration, measurement frequency, and dropout patterns. Their findings indicate that frequent measurements significantly reduce sample size requirements in short-term trials, while long-term trials are more suitable for detecting small slope differences. Additionally, incorporating dropout patterns into sample size calculations leads to more accurate estimations compared to traditional methods.