2.5. Sample Size and Statistical Analysis
Kawasaki
KAWASAKI
The target sample size was 80, assuming an ineligibility rate of approximately 10%. The sample size was calculated with the following assumptions: Cohen’s d = 0.80, type I error rate = 0.05, power = 80%, and the ratio of the two groups = 1:1. All participants, physicians, investigators, and analysts were blinded to the allocation information. The staff of Ortho Medico provided computer-generated random numbers using Statlight#11 Ver. 2.10 software (Yukms, Kawasaki, Japan). Data were described as means and SDs, median and minimum to maximum, or 95% confidence interval. The Chi-square test was used to compare sex and K-L grade between the two groups. Mean differences between two individual groups were analyzed by Welch’s 