Efficacy of EMG- and EEG-Biofeedback in Fibromyalgia Syndrome: A Meta-Analysis and a Systematic Review of Randomized Controlled Trials
Table 3
Effect sizes for all outcome measures.
Outcome
Type of effect
k
95%
P
Pain intensity
Pre-post
7 (167)
1.92
0.93–2.9
92
0.000
Pain intensity
Pre-follow-up
3 (65)
1.92
−0.13–3.98
95
0.07
Pain intensity
Controlled
7 (289)
0.79
0.22–1.36
79
0.006
Pain intensity
Follow-up controlled
2 (86)
0.86
−1.25–2.98
94
0.42
Sleep problems
Pre-post
2 (92)
0.41
−0.0–0.83
0
0.05
Sleep problems
Pre-follow-up
—
—
—
—
—
Sleep problems
Controlled
2 (87)
0.23
−0.20–0.65
0
0.29
Sleep problems
Follow-up controlled
—
—
—
—
—
Depression
Pre-post
4 (91)
0.72
−0.15–1.59
87
0.11
Depression
Pre-follow-up
3 (71)
0.71
−0.34–1.76
88
0.18
Depression
Controlled
4 (181)
0.37
−0.44–1.18
85
0.37
Depression
Follow-up controlled
3 (120)
0.8
−0.51–2.11
91
0.23
Fatigue
Pre-post
4 (117)
1.65
0.28–3.03
94
0.02
Fatigue
Pre-follow-up
3 (65)
1.78
−0.25–3.81
95
0.09
Fatigue
Controlled
4 (163)
0.38
−0.46–1.08
85
0.43
Fatigue
Follow-up controlled
—
—
—
—
—
HRQOL
Pre-post
4 (106)
2.05
0.40–3.69
95
0.01
HRQOL
Pre-follow-up
2 (34)
6.5
−5.7–18.7
98
0.3
HRQOL
Controlled
4 (163)
0.62
−0.77–2.02
93
0.38
HRQOL
Follow-up controlled
2 (68)
0.252
−2.94–7.98
97
0.37
Comparison of EMG-BFB and EEG-BFB
Pain intensity EMG
Pre-post
4 (86)
1.46
0.36–2.36
88
0.009
Pain intensity EMG
Pre-follow-up
—
—
—
—
—
Pain intensity EMG
Controlled
4 (162)
0.86
0.11–1.62
76
0.03
Pain intensity EMG
Follow-up controlled
—
—
—
—
—
Pain intensity EEG
Pre-post
3 (65)
2.8
0.41–5.19
96
0.02
Pain intensity EEG
Pre-follow-up
—
—
—
—
—
Pain intensity EEG
Controlled
3 (127)
0.71
−0.37–1.8
86
0.2
Pain intensity EEG
Follow-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.