Katz 2005.

Study characteristics
Methods	Design: cross‐over Duration: 7 weeks Assessment: baseline and post‐intervention Country: USA
Participants	Pain condition: low back pain Population: adults with chronic low back pain Minimum pain intensity: no Inclusion criteria ≥ 18 years and chronic low back pain for ≥ 3 months Exclusion criteria Any other significant physical or mental health comorbidity Total participants randomised: 54 Age in years (mean, SD): 50.6 (10.7) Gender: 26/54 were female Pain duration in years (mean, SD): NR
Interventions	Placebo Inert Matched dosing schedule Bupropion 300 mg NDRI Fixed dose with forced titration
Outcomes	Pain intensity SAEs Withdrawal
Missing data methods	ITT with LOCF
Funding source	Partly funded by pharmaceutical: "Supported in part by an investigator‐initiated research grant from GlaxoSmithKline"
Conflicts of interest	Supported in part by an investigator‐initiated research grant from GlaxoSmithKline to R.H.D., who has also received research support, consulting fees, or lecture honoraria in the past year from Abbott Laboratories, Eli Lilly & Co., Endo Pharmaceuticals, EpiCept Corporation, NeurogesX, Novartis Pharmaceuticals, Organon, Ortho‐McNeil Pharmaceutical, Pfizer, Purdue Pharma, Ranbaxy Corporation, Reliant Pharmaceuticals, Renovis, and UCB Pharma.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using a computer‐generated list of random numbers.
Allocation concealment (selection bias)	Unclear risk	Allocation procedures NR
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	States double‐blind and used same dosing for placebo as intervention but no information given regarding other blinding procedures
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Self‐reported outcomes from participants but uncertain of blinding procedures
Incomplete outcome data (attrition bias) All outcomes	High risk	ITT with LOCF Attrition Total: 14/54 (25.9%) Placebo: 5/54 (9.3%) Bupropion 300 mg: 9/54 (16.7%)
Selective reporting (reporting bias)	High risk	"Several other health‐related quality‐of‐life measures of physical and emotional functioning were administered, but these data were not analyzed because of the absence of significant beneficial effects on the pain intensity and relief outcome measures."
Other bias	Unclear risk	Participants tapering off of bupropion reported having AEs from reducing the medication, which could have lasted the washout period, but this is not explored further in the article.