Keefe 1990.

Study characteristics
Methods	RCT. 3 arms; assessed pre‐treatment, post‐treatment, 6 months
Participants	End of treatment n = 94 Start of treatment n = 99 Sex: 71 F, 28 M Mean age = 64.0 (SD 11.5) Source = rheumatology clinic Diagnosis = osteoarthritis of the knee Mean years of pain = 12.0
Interventions	"coping skills training" "arthritis education" "standard care"
Outcomes	Primary pain outcome: AIMS pain Primary disability outcome: AIMS physical disability Primary distress outcome: AIMS psychological disability Arthritis Impact Measurement Scale (AIMS): pain  AIMS: psychological disability AIMS: physical disability Pain behaviour (Keefe & Block) observation                        Coping Strategy Questionnaire                           Medication use
Notes	Funding statement: "Supported by NIAMS grant AR‐35270" Conflict of interest statement: None included in this paper CBT vs AC, post‐treatment and follow‐up: analyses 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 CBT vs TAU, post‐treatment and follow‐up: analyses 2.1, 2.2, 2.3, 2.4, 2.5, 2.6
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“randomly assigned (using a random number table)”
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data methods not described; attrition < 10%
Selective reporting (reporting bias)	Unclear risk	Trial protocol not published
Treatment expectations	Low risk	Treatment credibility assessed: no significant differences between the two groups identified