Bleijenberg 1994.
| Methods | Study design: randomised controlled trial Total study duration: Mean follow‐up 14 months (SD 8.9; range 3 to 28 months) for EMG biofeedback and 9 months (SD 7.0; range 3 to 26 months) for comparison group |
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| Participants | 21 patients, all with pelvic floor dyssynergia and constipation N = 11 electromyograph (EMG) biofeedback (8 female, 3 male) (mean age 35 years, range 20 to 50 years); duration of symptoms (mean 8 years, range 2 to 11years) N = 10 balloon biofeedback (8 female, 2 male) ‐ 1 drop out (mean age 40 years (range 28 to 47 years)); duration of symptoms (mean 7.5 years, range 2 to 15 years) No difference between groups at pre‐test |
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| Interventions | No laxatives allowed Weekly outpatient sessions for 8 weeks Intervention group: Phase 1: EMG biofeedback using anal‐plug electrode and digital display Phase 2: simulated defecation of oatmeal porridge Phase 3: toilet instructions ‐ to strain a maximum of 5 times on the toilet after each meal and patient to decide whether 'straining' was correct or not Comparison group: Phase 1: Balloon biofeedback using balloon catheter inflated with 20 mL air inserted 8 cm into rectum, patient to pull balloon out over 10 seconds without straining Phase 2 and 3 same as EMG biofeedback |
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| Outcomes | EMG quality score (based on depth and amplitude of EMG signal from 0 to 100: 0 = no relaxation during straining, 100 = maximal relaxation) Patient symptom diary (recorded 4 times daily): frequency, difficult evacuation, incomplete evacuation, hard stools, abdominal pain Constipation score (calculated from symptom diary) VAS (0 to 200: 100 = unchanged) of subjective rating of change SCL‐90 ‐ validated psychopathology symptom checklist |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding (performance bias and detection bias) All outcomes | High risk | Not blinded |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Low attrition (one participant only) |
| Selective reporting (reporting bias) | Unclear risk | Not registered on a clinical trials registry |
| Other bias | Low risk | The study appears to be free of other sources of bias |