Keefe 1996.

Methods	RCT; 3 arms; assessed at pre‐treatment, post‐treatment, 6 months, 1 year
Participants	End of treatment n = 82 Start of treatment n = 88 Sex: 54 F, 34 M Mean age = 62.6 (SD 10.1) Source = volunteer Diagnosis = osteoarthritis of knee Mean years of pain = 10.7
Interventions	"spouse‐assisted coping skills training" "coping skills training" "spouse‐supported arthritis education"
Outcomes	Primary pain outcome: AIMS pain Primary disability outcome: AIMS physical disability Primary mood outcome: AIMS mental disability Catastrophising outcome: none Arthritis Impact Measurement Scale (AIMS): pain                               Arthritis Impact Measurement Scale (AIMS): physical                           Arthritis Impact Measurement Scale (AIMS): psychological                      Coping Strategies Questionnaire: coping                              Coping Strategies: pain control                        Pain behaviour (Keefe & Block) observation
Notes	CBT versus active, post‐treatment: analyses 1.1, 1.2, 1.3 Yates quality scale: total quality = 25/35, design quality = 17/26, 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 (but equal credibility of treatments rated by participants)
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Fully reported; no differential attrition but no test for differences
Selective reporting (reporting bias)	Low risk	Fully reported
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not reported