Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Physical functioning
RCT	60 adults with CFS (CDC criteria) attending a secondary-care centre In review	Predefined increase in functional score (assessed by SF-36 questionnaire) 13 weeks 19/30 (63%) with CBT 5/30 (17%) with relaxation	RR 3.70 95% CI 2.37 to 6.31 NNT 3 95% CI 1 to 7	Moderate effect size	CBT
RCT 3-armed trial	153 adults with CFS (CDC criteria) In review	Change in functional score (assessed by SF-36 questionnaire) with group CBT with usual care Absolute results not reported	Absolute difference –1.63 for group CBT v usual care 95% CI –4.05 to +0.78		Not significant
RCT 3-armed trial	153 people with CFS (CDC criteria) In review	Change in functional score (assessed by SF-36 questionnaire) with group CBT with education and support Absolute results not reported	Absolute difference –1.23 for group CBT v education and support 95% CI –3.52 to +1.05		Not significant
RCT 4-armed trial	90 adults with a mean age of 39.6 years who fulfilled diagnostic criteria for CFS (not further defined) In review	Mean number of non-sedentary hours 7 months (3 months after completion of treatment) 5.2 with CBT plus placebo 5.2 with usual care plus placebo	Significance not assessed
RCT 4-armed trial	90 adults with a mean age of 39.6 years who fulfilled diagnostic criteria for CFS (not further defined) In review	Mean score for ability to participate in daily activities (Karnofsky performance score) 7 months (3 months after completion of treatment) 72.1 with CBT plus placebo 73.4 with usual care plus placebo	Significance not assessed
RCT 4-armed trial	114 adults with CFS (defined by CDC criteria); baseline physical functioning scores 46.36 in people receiving CBT, 53.77 in people receiving relaxation In review	Mean score on SF-36 for physical functioning 12 months 58.64 with CBT 61.20 with relaxation therapy	Significance not assessed
RCT	69 children and adolescents aged 10 to 17 years with CFS (CDC criteria)	Change in functional score (assessed by short-form [SF]-36 questionnaire) 5 months 27.3 with CBT 10.0 with no treatment	Absolute difference 17.3 95% CI 6.2 to 28.4	Effect size not calculated	CBT
RCT	63 adolescents aged 11–18 years with CFS (CDC or Oxford criteria) In review	Mean score on SF-36 for physical functioning 6 months post treatment 80.4 with family-focused CBT 64.0 with psycho-education	Adjusted mean difference +13.42 95% CI –2.14 to +29.00 P = 0.09 Mean difference adjusted for associated baseline values		Not significant
RCT	131 adolescents aged 12–18 years with CFS (CDC criteria) In review	Physical functioning (assessed by CHQ-CF87) 6 months 88.5 with internet CBT 70.1 with usual care	Mean difference 18.4 95% CI 12.9 to 23.9 P <0.0001	Effect size not calculated	CBT
RCT 4-armed trial	641 adults with CFS (Oxford criteria)	Mean score on SF-36 for physical functioning 52 weeks 58.2 with CBT 50.8 with specialist medical care	Mean difference 7.1 95% CI 2.0 to 12.1 P = 0.0068	Effect size not calculated	CBT