Table 3: Effect sizes for all outcome measures.

Outcome
Type of effectk 95% P

Pain intensityPre-post 7 (167)1.920.93–2.9920.000
Pain intensityPre-follow-up 3 (65)1.92 −0.13–3.98950.07
Pain intensityControlled 7 (289)0.790.22–1.36790.006
Pain intensityFollow-up controlled 2 (86)0.86 −1.25–2.98940.42
Sleep problemsPre-post2 (92)0.41−0.0–0.8300.05
Sleep problemsPre-follow-up
Sleep problemsControlled2 (87)0.23−0.20–0.6500.29
Sleep problemsFollow-up controlled
DepressionPre-post4 (91)0.72−0.15–1.59870.11
DepressionPre-follow-up3 (71)0.71−0.34–1.76880.18
DepressionControlled4 (181)0.37−0.44–1.18850.37
DepressionFollow-up controlled3 (120)0.8−0.51–2.11910.23
FatiguePre-post4 (117)1.650.28–3.03940.02
FatiguePre-follow-up3 (65)1.78−0.25–3.81950.09
FatigueControlled4 (163) 0.38 −0.46–1.08850.43
FatigueFollow-up controlled
HRQOLPre-post4 (106)2.050.40–3.69950.01
HRQOLPre-follow-up2 (34)6.5−5.7–18.7980.3
HRQOLControlled4 (163)0.62−0.77–2.02930.38
HRQOLFollow-up controlled2 (68)0.252−2.94–7.98970.37

Comparison of EMG-BFB and EEG-BFB
Pain intensity EMG Pre-post4 (86)1.460.36–2.36880.009
Pain intensity EMGPre-follow-up
Pain intensity EMGControlled4 (162)0.860.11–1.62760.03
Pain intensity EMGFollow-up controlled
Pain intensity EEG Pre-post3 (65)2.80.41–5.19960.02
Pain intensity EEGPre-follow-up
Pain intensity EEGControlled3 (127)0.71−0.37–1.8860.2
Pain intensity EEGFollow-up controlled

: number of studies in the analysis, : number of patients in the analysis.
Effect size, Hedges (significant effect sizes are marked in bold text).
CI: confidence interval.
Pre-post: effect size was computed for the difference of means between pretreatment and posttreatment (short-term efficacy).
Pre-follow-up: effect size was computed for the difference of means between pretreatment and the longest available follow-up (long-term efficacy).
Controlled: Effect size was computed for the group mean at posttreatment in comparison to a control group mean at posttreatment (short-term efficacy, controlled).
Follow-up controlled: effect size was computed for the group mean at the latest follow-up in comparison to a control group mean at posttreatment (long-term efficacy, controlled).
EMG BFB: electromyography biofeedback.
EEG BFB: electroencephalogram biofeedback.
EMG: subgroup of studies using EMG BFB.
EEG: subgroup of studies using EEG BFB.