Valle‐Jones 1992.

Methods	RCT
Participants	Subjects: 216 patients with non‐specific LBP; 97 women, 113 men and 6 'unknown'. Mean age 43, median duration of symptoms 11 days. Inclusion criteria: 1) first episode of non‐specific LBP, 2) chronic non‐specific LBP, 3) acute exacerbation of a longer‐standing problem.
Interventions	Treatment intervention: 1) Back support (n=111), elasticised with an attached silicone rubber pad of special shape, 3 weeks. Control intervention: 2) Standard therapy: advice on rest and lifestyle (n=105).
Outcomes	Pain, limitation of activity, overall improvement, ability to work and use of analgesics; all significantly better in lumbar support group after 3 weeks.
Notes	No data on compliance.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Unclear from text
Allocation concealment?	High risk	C ‐ Inadequate
Blinding? All outcomes ‐ patients?	High risk
Blinding? All outcomes ‐ outcome assessor?	High risk
Incomplete outcome data addressed? All outcomes ‐ drop‐outs?	Low risk
Incomplete outcome data addressed? All outcomes ‐ ITT analysis?	Low risk
Similarity of baseline characteristics?	Unclear risk	Unclear from text
Co‐interventions avoided or similar?	Low risk
Compliance acceptable?	High risk	No data on compliance
Timing outcome assessments similar?	Low risk