Rini 2015.

Study characteristics
Methods	RCT; 2 arms; assessed pretreatment, 5 weeks (post‐treatment), and 9 to 11 weeks (post‐treatment)
Participants	Start of treatment: N = 113 Post‐treatment: N = 109 Sex: 91 F, 22 M Mean age: 67.62 years (SD 9.45) Diagnosis: osteoarthritis knee or hip Mean years of pain: NR
Interventions	Intervention name: PainCOACH Psychological approach: CBT Duration: 8 weeks Control type: assessment only (no details of TAU)
Outcomes	Primary pain outcome: AIMS2 – Pain subscale Primary disability outcome: AIMS2 – subscales relevant to lower extremity functioning Primary quality‐of‐life outcome: none Adverse events: none Primary anxiety outcome: PASS‐20 Primary depression outcome: none Intervention satisfaction: none Intervention engagement: none Other outcome measures: self‐efficacy for pain management (Arthritis Self‐Efficacy Scale), positive and negative affect (Positive and Negative Affect Scale), sociodemographic and medical variables (AIMS2)
Notes	Funding: National Institute of Arthritis and Musculoskeletal Skin Diseases (National Institutes of Health). Part funding from Johnston County Osteoarthritis Project (from which some participants in this trial were derived), which is supported in part by cooperative agreements S043, S1734, and S3486 from Centers for Disease Control (CDC) and Prevention/Association of Schools of Public Health; NIAMS Multipurpose Arthritis and Musculoskeletal Disease Center grant 5‐P60‐AR30701; and NIAMS Multidisciplinary Clinical Research Center grants 5‐P60‐AR49465 and P60‐AR064166 Conflicts of interest: none (CR: payment from a grant supporting the study (institution/past), financial relationship (employment/ongoing UNC‐Chapel Hill), grants pending, receiving travel/accommodation/meeting expenses related to NIH grant review. LSP, TJS, DCM, MS, GW, DKA, RG, JLS, CM, JMJ, DSC: payment from a grant supporting the study (institution/past). MS: employment at EMG Serono Inc, ownership of stock in BMS, AbbVie, Abbott labs. GW: consultancy payment/honorarium (ongoing), fees for participating in review activities, payment for writing/reviewing manuscript. DKA: consultation fee for honorarium from UNC‐Chapel Hill. RG: employment with Memorial Hospital of RI. JLS: employment at UNC‐Chapel Hill. CM: employment at Duke. CP: employment at UNC‐Chapel Hill. JMJ: consultancy and grants pending. FJK: nothing to declare). Country: USA Trial registration: NCT01638871 Intervention development, intervention delivery, and percentage interaction of healthcare professional obtained and confirmed by study authors upon contact
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A computer‐generated permuted block sequence was used and was stratified by sex and age.
Allocation concealment (selection bias)	Low risk	Sequentially‐numbered opaque envelopes were used to conceal the allocation until after baseline assessments.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Staff blinded at baseline and post‐assessment; unblinded staff at midpoint called to ask participants to complete and post‐return questionnaires they already had in their possession (staff member did not take the assessment measures)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rate in both groups < 10%
Selective reporting (reporting bias)	High risk	Prospectively registered. Secondary outcomes updated after study start date. More outcomes were reported in registry than the publication (change in bodily relaxation; behavioural observation task for ‘change in problem‐solving’; open‐ended questions on programme usability; medication type and frequency of use across the study (baseline/midtreatment/post‐treatment); adapted CSQ‐R, CPCI subscales, WHYMPI subscales, and additional items that measure use of strategies taught; TIPI). Also, 6 months FU in registry: not mentioned in article. Many means reported are unadjusted (Table 3) despite use of covariates. Some adjusted means reported in text (e.g. pain) but only when significant, and for pain, no reported analysis of full sample (women only) (clinicaltrials.gov/ct2/show/record/NCT01638871)