| Study characteristics |
| Methods |
Parallel RCT.
Comparing the effects of therapy that it is targeted with aim of facilitating physiotherapy and when it is aimed at increasing relaxation. |
| Participants |
N = 26.
Aged 10 ‐ 41 years.
Groups matched by age and severity of disease using Shwachman‐Kulczycki scoring system prior to randomisation. |
| Interventions |
1. Biofeedback assisted breathing re‐training (N = 13).
2. Biofeedback assisted relaxation training (N = 13).
8 sessions over 4 weeks.
Delivered by psychology and biofeedback students under supervision. |
| Outcomes |
Lung function:
1. FVC;
2. FEV1;
3. FEF 25-75%.
Evaluation at:
1. 3 pre‐study assessments, 18 months prior to study commencement;
2. baseline;
3. post‐study;
4. follow up. |
| Notes |
POI: Pulmonary function.
The groups were equivalent at baseline on age, severity of disease, height, weight, and pre‐treatment lung functions.
Both groups believed they were being given an intervention so effective blinding of participants ‐ no information about blinding of trainers and pulmonary function technicians.
Not clear how sample was selected or from what population they were drawn.
Analysed as ITT apart from one missing matched pair in FEV1 outcome measure.
Limited follow‐up data. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Details of random generation process were not provided by the authors. They just reported that 'subjects were screened medically, matched by age and severity disease, and randomly assigned to either the experimental group receiving the biofeedback‐assisted BRT or to the control groups receiving peripheral temperature biofeedback‐assisted relaxation training (RLXT)' (Delk 1994, p. 23). |
| Allocation concealment (selection bias) |
Unclear risk |
The method of concealment is not described. |
| Blinding (performance bias and detection bias)
All outcomes |
Unclear risk |
Due to the nature of the intervention blinding of participants is not possible adequately. Insuffiecent information about blinding of outcome assessment available, |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Outcomes were analysed as intention‐to‐treat, but it has to be mentioned that for FEV1 results of one participant is missing (n = 25). Reasons were not explained by the authors. |
| Selective reporting (reporting bias) |
Unclear risk |
Information is insufficient to judge whether 'low' or 'high' risk. |
