Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Physical functioning
RCT Crossover design	25 people with CFS (CDC criteria) In review	Mean change in short-form (SF)-36 physical functioning score 6 weeks +6.5 with fludrocortisone –1.6 with placebo	P = 0.15 Results should be interpreted with caution, as it is possible that treatment effects may persist after crossover		Not significant