Abou‐Raya 2012.

Study characteristics
Methods	Design: parallel Duration: 16 weeks Assessment: baseline and post‐intervention Country: Egypt
Participants	Pain condition: knee OA Population: older adults (aged ≥ 65) with knee OA Minimum pain duration: ≥ 40 on 0 ‐100 scale Inclusion criteria ACR clinical and radiographic criteria of primary knee OA Mean knee pain intensity of at least ≥ 40 on 0‐100 scale preceding week Knee pain > 14 days/month during 3 consecutive months preceding enrolment Exclusion criteria Morbid obesity (BMI > 32 kg/m2), joint inflammatory diseases and or crystal‐induced arthropathies, or any other concomitant disease (such as neuropsychiatric disease including cognitive impairment, Alzheimer’s disease, Parkinson’s disease, cerebrovascular disease, cardiovascular disease, liver and renal disease) Taking any other antidepressants that could interfere with the evaluation of the intervention Total participants randomised: 288 Age in years (mean, SD): 68.5 (SD NR) Gender: 241/288 were female
Interventions	Duloxetine 144 participants 60 mg/day Placebo 144 participants Matched to duloxetine
Outcomes	Pain intensity Physical function Mood AE SAE Withdrawal
Missing data methods	ITT but method not specified
Funding source	Non‐pharmaceutical: sponsored by University of Alexandria, Egypt
Conflicts of interest	Author conflicts of interest NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised by a clinical pharmacist using a computerised random number list.
Allocation concealment (selection bias)	Low risk	Allocation was concealed in sealed envelopes.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, and placebo was identical to duloxetine.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes by blinded participants
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	States ITT but no imputation method reported Attrition: Total: 34/288 (11.8%) Placebo: 13/144 (9.0%) Duloxetine 60 mg: 21/144 (14.6%)
Selective reporting (reporting bias)	Unclear risk	Protocol registered retrospectively: https://clinicaltrials.gov/show/NCT01425827 2011: Pain is the only stated outcome in the trial registry
Other bias	Low risk	No other sources of bias were identified.