Study characteristics
| Author, year (reference) | Diagnostic criteria | Setting | Study design | Intervention | Sample at baseline (n) | Sample at follow-up n (% baseline) | Mean age (SD) (range) | Sex n/total at baseline (% female) | Follow-up (SD)(range) |
| Chalder et al, 200214 | CDC/Oxford | Tertiary | Observational | Family-focused CBT: up to 15 1-hour sessions | 23 | 18 (78%) | NR (11–18) | 20/23 (87%) | 6 months |
| Chalder et al, 201023 | CDC/Oxford | Tertiary | RCT | Family-focused CBT (13 fortnightly 1-hour sessions) vs pyschoeducation | 63 | NR NR 59 (94%) | NR (13.0–17.0) | 43/63 (68%) | 3 months 6 months 12 months |
| Lloyd et al, 2012 (follow-up of Chalder et al, 2010)21 | CDC/Oxford | Tertiary | RCT | Family-focused CBT (13 fortnightly 1-hour sessions) vs psychoeducation | 63 | 44 (70%) | 15 (1.7) (11–18) | 32/63 (51%) | 24 months |
| Crawley et al, 20113 | NICE | School | Observational | Specialist medical care offered to those diagnosed with CFS/ME | 23 | NR 19 (83%) | 14.6 (1.5) | 17/23 (74%) | 1.5 months 6 months |
| Katz et al, 200918 | CDC | Secondary/tertiary | Observational | No intervention | 39 | 36 (92%) 33 (85%) | NR | 35/39 (90%) | 6 months 18 months |
| Lim and Lubitzl, 200224 | CDC | Tertiary | Observational | Four-week intensive multidisciplinary inpatient programme | 57 | 42 (74%) | 15 (10–19) | 50/57 (88%) | 3.5 years (3 months to 5 years) |
| Nijhof et al, 201215 | CDC | Tertiary | RCT | Internet-based CBT vs usual care | 135 | 131 (97%) 127 (94%) | 15.9 (1.3) | 111/135 (82%) | 6 months 12 months |
| Nijhof et al, 2013 (follow-up of Nijhof et al, 2012)22 | CDC | Tertiary | Long-term follow-up of RCT | Internet-based CBT vs usual care (with post-RCT crossover) | 127 | 112 (88%) | 15.8 (1.4) | 105/127 (83%) | 2.7 years (0.5)(1.7–3.8 years) |
| Rowe, 199919 | CDC | Tertiary | RCT | Gammaglobulin vs placebo | 89 | 86 (97%) | NR | NR (NR) | 56 months (25 months)(15–112 months) |
| Stulemeijer et al, 200520 | CDC | Tertiary | RCT | CBT (10 sessions) vs waiting list | 69 | 62 (90%) | 15.7 (1.3) | 62/69 (90%) | 5 months |
| Van Geelen et al, 201017 | CDC | Tertiary | Observational | Regular care | 60 | 54 (90%) | 16.0 (1.5) | NR (79.6%) | 2.2 years (1.6) |
| Viner et al, 200416 | Modified CDC | Tertiary | Observational | Rehabilitative programme vs supportive care | 78 | 56 (72%) 32 (41%) 24 (31%) 17 (22%) | 14.2 (9–17) | 49/78 (63%) | 6 months 12 months 18 months 24 months |
CBT, cognitive-behavioural therapy; NR, not reported; RCT, randomised controlled trial.