No significant differences in absolute steroid levels were observed between the ME/CFS and control groups, either in the combined cohort or within gender-stratified groups. However, this may reflect limited statistical power rather than the absence of true biological differences. To explore this, we estimated the sample sizes required to detect the effects sizes (Cohen’s d) derived from the present dataset (Table 2) using a significance threshold of α = 0.05 and a statistical power of 0.80.
