Jackel 1990.

Methods	RCT conducted in Germany
Participants	71 patients randomised, 62% female, average age 48.7 years, mean duration of pain 12.8 years
Interventions	MBR (Therapy): 4‐6 weeks of daily therapy. Physical therapy 2x/ day in pool, 1x/ day in gym. Education: anatomy, lifting instructions. 8‐10x mudbaths, 8x massage, 8x electro therapy. Psychology: pain beliefs, coping, depression, impact of pain on life Waiting‐list (control)
Outcomes	Pain, Disability (0‐10 Activities of daily living scale) Follow‐up: ST (4 weeks)
Notes	Subgroup analyses: High intensity intervention, Low baseline symptom intensity (<60% of maximum scale score). Included in Guzman 2006
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 of participants	High risk	Not possible
Blinding of clinicians	High risk	Not possible
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not possible; patient reported outcome
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not reported
Intention to treat analysis	Unclear risk	Not stated
Selective reporting (reporting bias)	Unclear risk	No protocol
Comparability of groups at baseline	Low risk	Table 2/3. Comparable on clinical characteristics
Compliance	Unclear risk	Not stated
Cointerventions	Unclear risk	Not stated
Timing of assessment	Low risk	Tables 2/3. 4 weeks