Konno 2016.

Study characteristics
Methods	Design: parallel Duration: 14 weeks Assessment: baseline and post‐intervention Country: Japan
Participants	Pain condition: low back pain Population: adults aged 20‐80 with chronic low back pain Minimum pain intensity: ≥ 4 on 0‐10 scale Inclusion criteria Outpatients of age 20 to < 80 years who had low back pain persisting for at least 6 months Used NSAIDs for at least 14 days per month for an average of 3 months before the start of the study and for at least 14 days during the 1‐month period before the start of the study Pain intensity ≥ 4 on 0‐10 scale Exclusion criteria Low back surgery, current invasive treatment for low back pain Depression and suicidal risk Total participants randomised: 458 Age in years (mean): 58.9 Gender: 237/458 were female Pain duration in years (mean): 10.1
Interventions	Placebo n = 226 Inert Identical appearance to duloxetine Duloxetine 60 mg n = 232 SNRI Fixed dose, forced titration
Outcomes	Pain intensity Sleep Quality of life Physical function Mood Moderate pain relief Substantial pain relief PGIC AEs SAEs Withdrawal
Missing data methods	MMRM and LOCF, BOCF as sensitivity analysis for pain
Funding source	Pharmaceutical: Shionogi & Co. Ltd., Eli Lilly Japan K.K., and Eli Lilly and Company funds were received in support of this work.
Conflicts of interest	Relevant financial activities outside the submitted work: consultancy, employment
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using a stochastic minimisation procedure
Allocation concealment (selection bias)	Low risk	An "investigator in charge of blinding" randomly assigned participants to a treatment arm based on an assignment table. This assignment table was sealed and was inaccessible to all parties until after the clinical report was finalised.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, identical study drugs and matched dosing
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes by blinded participants
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition rates. Mixture of analyses for primary outcome including MMRM, LOCF and BOCF. Results were the same across all missing data analyses. Attrition Total: 49/458 (10.7%) Placebo: 26/226 (11.5%) Duloxetine 60 mg: 23/232 (9.9%)
Selective reporting (reporting bias)	Low risk	All outcomes were prospectively registered on clinicaltrials.gov
Other bias	Low risk	No other sources of bias were identified