Ozturk 2006.

Methods	RCT; method unknown.
Participants	46 participants (24 in the traction group, 22 in the control group) hospitalized with the diagnosis of lumbar disc herniation. Participants had LBP or sciatica, pain duration < 6 months and lumbar disc herniation verified by CT scan. People with LBP due to neoplastic, inflammatory, infectious or metabolic causes were excluded. Mean age: T) 40.2 years, C) 52.7 years.
Interventions	T) Traction: physiotherapy programme, including hot pack, ultrasound and diadynamic current, and traction: continuous lumbar traction with Enraf Nonius Traction Eltrac 439. In total, 15 sessions, 5 sessions per wk, 15 min per session, traction force 255‐0% of body weight. C) Comparison intervention: physiotherapy programme without traction.
Outcomes	Assessment before and immediately AT. VAS for pain (mean (SD)) AT: T) 2.4 (1.7), C) 3.6 (2.7).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No mention of randomization procedure.
Allocation concealment (selection bias)	Unclear risk	No information provided on allocation concealment.
Blinding (performance bias and detection bias) All outcomes ‐ participants	High risk	No mention of attempts to blind the participants. It is unlikely that the participants were blinded.
Blinding (performance bias and detection bias) All outcomes ‐ providers	High risk	No mention of attempts to blind the care providers. It is unlikely that the care providers were blinded.
Blinding (performance bias and detection bias) All outcomes ‐ outcome assessors	High risk	No mention of attempts to blind the outcome assessors.
Incomplete outcome data (attrition bias) All outcomes ‐ loss to follow‐up	Unclear risk	It is not clear how many participants were lost to follow‐up.
Incomplete outcome data (attrition bias) All outcomes ‐ intention to treat analysis	Unclear risk	It is not clear whether an intention‐to‐treat analysis was used.
Selective reporting (reporting bias)	Low risk	Published results included all prespecified outcomes.
Group similarity at baseline (selection bias)	Unclear risk	No mention of group characteristics at baseline.
Influence of co‐interventions (performance bias)	Low risk	No co‐interventions were used during the treatment period.
Compliance with interventions (performance bias)	Unclear risk	Not mentioned.
Timing of outcome assessments (detection bias)	Unclear risk	Unclear at what time outcome assessments (for all intervention groups) were measured.