Hadadian 2018.

Study characteristics
Methods	Study design Parallel RCT Study dates Duration of follow‐up: 1 month Time frame: 2011 (months were not reported)
Participants	Study characteristics Setting: single centre (Imam Reza Hospital in Kermanshah) Country: Iran Inclusion criteria: receiving HD treatment for at least 6 months; willingness to participate in the study; ≥ 15 years; complete awareness of the situation; hearing and speaking ability as needed to learn the technique; and no psychological disease Exclusion criteria: lack of willingness to learn relaxation technique; failure to attend the training course; hospitalization for whatever reason; encountering physical or mental problems during the study Baseline characteristics Number (analysed/randomised): intervention group (not reported/27); control group (not reported/38) Mean age ± SD (years): overall (52.66 ± 2.007) Sex (M/F): overall (28/37) Dialysis type: HD Dialysis vintage (years) (mean ± SD): not reported Comorbidities CVD: not reported Diabetes: not reported Hypertension: not reported Depression (clinician diagnosis): not reported
Interventions	Intervention classification Non‐pharmacological intervention Indication: study targeting fatigue Intervention group Progressive muscle relaxation Control group No treatment Co‐interventions Not reported
Outcomes	Outcomes reported Fatigue outcome measures used: validation data available Fatigue BFI (Appendix 3)
Notes	Additional information Funding: Research and Technological department of the University Conflicts of interest/disclosures: none Trial registration identification number: not reported A priori published protocol: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Sequence generation methods were not reported in sufficient detail to permit judgement
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment was not reported in sufficient detail to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not reported. However, interventions were different and participants and/or investigators could be aware of the treatment assigned
Blinding of outcome assessment (detection bias) All outcomes	High risk	It was not clear how fatigue was assessed, although an appropriate measure was used. However, subjective measures were used, it was not stated whether outcomes were assessed without knowledge of treatment allocation, and knowledge of treatment assignment may have influenced reporting. Participant/investigators beliefs about the superiority/inferiority of either intervention could have influenced their assessment of the outcome, but there was no evidence that this was likely
Incomplete outcome data (attrition bias) All outcomes	High risk	Not reported in sufficient detail to perform adjudication
Selective reporting (reporting bias)	High risk	Information about the protocol and the statistical analysis plan were not reported. Fatigue was not clearly reported. Fatigue was reported in a format that was not extractable for meta‐analysis. All outcomes that should be addressed (fatigue, cardiovascular disease, and death) were not reported
Other bias	Unclear risk	Baseline characteristics were not clearly reported. Funding was unlikely to influence the data analysis