Turner 1988.

Methods	RCT; 3 arms; assessed at pre‐treatment, post‐treatment, 6 months, 1 year
Participants	End of treatment n = 53 Start of treatment n = 81 Sex: 30 F, 51 M Mean age = 46.0 (SD not given) Source = pain or rehabilitation clinic Diagnosis = CLBP Mean years of pain = 6.2
Interventions	"CBT" "operant behavior therapy" "waiting list"
Outcomes	Primary pain outcome: MPQ PRI Primary disability outcome: SIP patient‐rated Primary mood outcome: none available Catastrophising outcome: CEQ Multidimensional Pain Questionnaire: Pain Response Index Sickness Impact Profile: patient‐rated Sickness Impact Profile: spouse‐rated Pain behaviour (Keefe & Block) observation Pain Behavior Checklist patient‐rated                    Pain Behavior Checklist spouse‐rated                    Cognitive Errors Questionnaire
Notes	CBT versus TAU, post‐treatment (waiting list not followed up): analyses 3.1, 3.2 BT versus TAU, post‐treatment (waiting list not followed up): analyses 7.2 Yates quality scale: total quality = 23/35, design quality = 15/26, treatment quality = 8/9
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	“randomly assigned”
Allocation concealment (selection bias)	High risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition fully reported; no test for differences
Selective reporting (reporting bias)	Low risk	Partially reported but full account of excluded measures
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not reported