NCT01510457.

Study characteristics
Methods	Design: parallel Duration: approximately 8 weeks Assessment: baseline and post‐intervention Country: USA
Participants	Pain condition: knee OA Population: adults with knee OA Minimum pain intensity: ≥ 4 on 0‐10 scale Inclusion criteria Confirmed knee OA Chronic pain for ≥ 6 months Average pain rating of worse knee is ≥ 4 on a 0‐10 scale Exclusion criteria Severe or untreated psychiatric disorder (e.g. depression, anxiety) Severe ongoing or unaddressed medical conditions Total participants randomised: 46 Age in years (mean, SD): 56 (8) Gender: 23/46 were female Pain duration in years (mean, SD): NR
Interventions	Placebo n = 17 Inert Identical appearance and matched dosing Milnacipran 100 mg‐200 mg n = 29 SNRI Forced titration to fixed doses
Outcomes	Pain intensity Mood Physical function AEs SAEs Withdrawal
Missing data methods	Completer analysis only
Funding source	Pharmaceutical: Forest Laboratories
Conflicts of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation methods not specified
Allocation concealment (selection bias)	Unclear risk	Allocation procedures not specified
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinded procedures, but 0 placebo participants reported AEs and 34% of milnacipran participants did report AEs, somewhat unblinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Self‐reported outcomes from participants, unsure of blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	Completer‐only analysis Attrition Total: 8/46 (17.4%) Placebo: 5/17 (29.4%) Milnacipran 100‐200 mg: 3/29 (10.3%)
Selective reporting (reporting bias)	Unclear risk	As we're using all outcomes from trial they report all registered outcomes BUT they first posted the trial in 2012, the trial started in 2010.
Other bias	High risk	Not published ‐ trial registry report only