Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Overall improvement
RCT	65 people with CFS (CDC 1998 criteria) In review	Proportion of people with improvement of at least 5 points on self-rated 100-point scale 12 weeks 53% with hydrocortisone (25–35 mg/day) 29% with placebo Absolute numbers not reported	P = 0.04 Clinical significance of this difference is unclear	Effect size not calculated	hydrocortisone