Table 5. Reviews reporting psychological/behavioural intervention subgroup differences.

Study	Sub-group
Castell et al. [43]–CFS	Analysis: Interventions with more treatment hours were more effective. No difference by intervention length, treatment settings, format, control group, illness duration, diagnostic criteria and study quality.
Malouff et al. [57]–CFS	Analysis: correlations between intervention effectiveness and hours of treatment, number of session, months of follow-up and study quality. Trend of large effect for physical fatigue and small for mental fatigue. No difference between subjective and objective fatigue.
Price et al. [58]—CFS	Analysis: Interventions conducted individually, compared to treatment as usual (versus waiting list) and incorporating increased activity were more effective. No difference by number of sessions.
Picariello et al. [54]–ESKD	Analysis: Interventions with non-fatigued samples at baseline and comparing to active controls did not reduce fatigue, whereas fatigued samples and comparing to non-active controls did. Interventions with facilitators with lower levels of training were more effective. Stress management/relaxation based interventions were more effective than those without. No significant difference by CBT based interventions or not.
Wendebourg et al. [59]–MS	Analysis: CBT based approaches more effective than other techniques (energy conservation, multi-disciplinary self-management, mindfulness). Individual approaches more effective than group settings.
Ulrichsen et al. [52]–Mindfulness	Observation: Intervention studies using fatigue cut-off points and measuring mental fatigue reported increased effects.