Table 1: Main study characteristics.

Author;
country;
year;
setting;
referral or recruitment
Mean age;  
female %;
race %
Diagnosis of Study populationTreatment groupControl group Both groupsOutcomes used for meta-analysis
latest follow up
screened/ randomized (%);
completing therapy (%)
Type of treatment;  
duration of treatment;
at baseline/ completing therapy (%)
Type of treatment;  
duration of treatment;
at baseline/ completing therapy (%)
Comedication allowed;
attendance rates (all sessions);
side effects;
drop out due to side effects in treatment group

Babu et al.;
India;  
2007;  
outpatient;
not reported 
[34]
39;  
70%; 
Not reported
criteriaNot reported/30;
30 (100%) 
;  
6 individual sessions of 45 minutes;  
15/15 (100%)
Sham EMG-BFB;  
6 individual sessions of 45 minutes;  
15/15 (100%)
not reported;  
not reported;  
not reported;  
not reported
Pain 0–10* 
Sleep VAS 0–10** 
Fatigue VAS 0–10** 
Depression VAS 0–10** 


Total VAS 0–80*No follow-up

Buckelew et al.;
USA;  
1998;  
outpatient;
university hospital, private practice 
[33]
44;  
90.8%; 
not reported
Yunus criteria240/119 (49.6%); 
109 (91%)
EMG-BFB and relaxation;
6-week individual treatment once a week for 1.5–3 hours;  
29/27
(93.1%)
Attention control;  
6-week individual treatment once a week for 1.5–3 hours; 30/28 (93.3%)
Yes 
not reported;  
not reported;  
not reported
Pain VAS 0–10* 
Sleep VAS 0–10* 
Fatigue
Depression
HRQOL NA
24 months

Ferraccioli et al.;  
Italy;
1987;
outpatient;
consecutive patients at an outpatient clinic 
[35]
57;  
100%; 
not reported
Not exactly specifiedNot reported/12;  12/12 (100%)EMG-BFB;
15 sessions, two sessions a week;  
6/6 (100%)
Sham EMG-BFB; 15 sessions; 6/6 (100%)Allowed;  
not reported;  
not reported;  
none
Pain VAS 0–10 
Sleep NA
Fatigue NA 
Fatigue NA 
Depression NA 
HRQOL NA
No follow-up

Kayiran et al.;
Turkey;
2010;
outpatient; consecutive patients at an outpatient clinic 
[39]
32;  
100%; 
not reported
ACR 
criteria
Not reported/40;  36 completing the first follow-up (90%) ; 20 individual sessions of 30 minutes;  
20/18 completing the first follow-up (90%)
Escitalopram (an ) 10 mg/day;  
8 weeks;  
20/18 completing the first follow-up (90%)
not allowed;  
not reported;  
not reported;  
not reported
Pain VAS 0–10 
Sleep NA 
Fatigue VAS 0–10 
Depression
( 0–63)  
HRQOL 
FIQ 
Total VAS 0–80
4 months

Kravitz et al.;
USA;
2006;
outpatient;
at two private practices and via advertisement and self-help groups 
[36]
46.9;  
92%; 
92% white
ACR 
criteria
159/64 (40.3%); 
59 (92.2%)
EEG-BFB;  
22 sessions;  
33/31 (93, 9%)
Sham EEG-BFB;
22 sessions; 31/28 (90.3%)
Morphines, SSRIs, and Benzodiazepines not allowed, other medication allowed;
74% reported side effects of EEG-BFB, e.g. fatigue, headache and sleep problems;  
not reported
Pain VAS 0–10
Sleep VAS 0–10
Fatigue VAS 0–10
Depression VAS 0–10
HRQOL
FIQ
Total VAS 0–80** 
1 week

Nelson et al.;
USA;
2010;
outpatient;
FMS database and advertisement 
[38]
51.6;
100%;
88.2% white
ACR
criteria
82/42 (51.2%);
34 (81%)
EEG-BFB;
22 sessions; 
21/17 (81%)
Sham EEG-BFB; 22 sessions;
21/17 (81%)
Allowed;
not reported;  
none;
none
Pain VAS 0–10* 
Fatigue VAS 0–10* 
Sleep MOS Sleep
NRS 0–100 
Depression PHQ 9
HRQOL 
FIQ 
Total VAS 0–80
6 months

Van Tulder et al.;  
the Netherlands;   2001;  
 outpatient; 
central registry 
[8]
;  
 100%; 
 not reported
ACR 
criteria
(53.4%); 
118 (82.5%)
EMG-BFB;  
16 sessions;  
50/43 (86%)
Treatment as usual; consecutive medical care; 29/28 (96.55%)Allowed;  
88% of patients attended 67% of BFB sessions;  
2 patients reported stress due to ;  
2 patients
Pain VAS 0–10 
Sleep NA 
Fatigue VAS 0–100 
Depression NA
HRQOL
Total (NRS 0–100)
6 months

FMS: fibromyalgia syndrome; ACR: American College of Rheumatology; EMG-BFB: electromyography biofeedback; VAS: visual analogue scale; HRQOL: health-related quality of life; FIQ: Fibromyalgia Impact questionnaire; The study included 4 different conditions. The analysis was performed with two of these conditions (Biofeedback and attention control); the numbers represent all four groups; NA: not assessed; CES: center for Epidemiological Studies Depression Scale; EEG-BFB: electroencephalography biofeedback (Neurofeedback); SSRI: selective serotonin reuptake inhibitor (an antidepressant); BDI: Beck Depression Inventory; NRS: Numeric Rating Scale; MOS: Medical Outcomes Study Sleep Scale; PHQ 9: Patient Health Questionnaire, In the BFB group; the study included 3 different conditions. The analysis was performed with two of these conditions (biofeedback and treatment as usual control); the numbers represent all three groups. BFB: biofeedback; SIP: sickness impact profile.
Note: Studies are presented in alphabetical order.
*Data provided on request.
**Data not provided on request.