Table 3.
Effect sizes for all outcome measures.
| Outcome |
Type of effect | k (n)1 | g 2 | 95% CI3 | I 2 | P |
|---|---|---|---|---|---|---|
| Pain intensity | Pre-post4 | 7 (167) | 1.92 | 0.93–2.9 | 92 | 0.000 |
| Pain intensity | Pre-follow-up5 | 3 (65) | 1.92 | −0.13–3.98 | 95 | 0.07 |
| Pain intensity | Controlled6 | 7 (289) | 0.79 | 0.22–1.36 | 79 | 0.006 |
| Pain intensity | Follow-up controlled7 | 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-BFB8 and EEG-BFB9 | ||||||
| Pain intensity EMG10 | 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 EEG11 | 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 | — | — | — | — | — |
1 k: number of studies in the analysis, n: number of patients in the analysis.
2Effect size, Hedges g (significant effect sizes are marked in bold text).
3CI: confidence interval.
4Pre-post: effect size was computed for the difference of means between pretreatment and posttreatment (short-term efficacy).
5Pre-follow-up: effect size was computed for the difference of means between pretreatment and the longest available follow-up (long-term efficacy).
6Controlled: Effect size was computed for the group mean at posttreatment in comparison to a control group mean at posttreatment (short-term efficacy, controlled).
7Follow-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).
8EMG BFB: electromyography biofeedback.
9EEG BFB: electroencephalogram biofeedback.
10EMG: subgroup of studies using EMG BFB.
11EEG: subgroup of studies using EEG BFB.