Strober 2011

Methods	RCT, placebo‐controlled, double blind Date of study: July 2008‐April 2009 Location: 41 centres in the USA
Participants	Randomised: 211 participants (mean age 45 years, 131 male) Inclusion criteria ‐Participants with moderate‐severe psoriasis (PGA ≥ 3, PASI ≥ 12, BSA ≥ 10), age ≥ 18 years Exclusion criteria Previous exposure to either etanercept or ABT‐874 Dropouts and withdrawals 18/211 (8.5%): etanercept 12, placebo 6 Time and reasons: Etanercept: AE (3), lost to follow‐up (1), withdrew consent (3), protocol violation (4), other (1) Placebo: AE (2), lost to follow‐up (1), protocol violation (2), other (1)
Interventions	Intervention A. Etanercept (n = 139), SC auto‐administered, 50 mg twice a week, 11 weeks Control intervention B. Placebo (n = 72), SC auto‐administered, twice a week
Outcomes	Assessments at 12 weeks Primary outcomes of the trial PASI 75 PGA 0/1 Secondary outcomes of the trial At 4, 8, 12 weeks PASI 50 PASI 75 PASI 90 DLQI PGA Safety Patient global assessment of psoriasis
Notes	Funding source, quote (Appendix 1): "Abbott Laboratories funded this study and participated in the study design, data collection, data management, data analysis and preparation of the manuscript. All of the authors had full access to the data and were involved in the analysis of data, development and revision of the manuscript, and decision to submit the manuscript for publication. The corresponding author takes responsibility for the integrity of the data and the accuracy of the data analysis." Declarations of interest (appendix 1): "B.E.S. has been an investigator, consultant, speaker, and served on an advisory board for Amgen, Abbott and Centocor; and has also been a speaker for Astellas. J.J.C. has received research support from Abbott, Amgen, Centocor, Celgene and Eli Lilly; has been a consultant for Abbott, Amgen and Centocor; and has been a speaker for Abbott. P.S.Y. has served as a consultant, principle investigator, speaker or advisory board member for Abbott, Amgen, Astellas and Centocor. M.O. and D.A.W. are employees of Abbott."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (p 662): "Patients were randomised..." Comment: no description of the method used to guarantee random sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote (p 662): "Patients were randomised" Comment: no description of the method used to guarantee allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote (p 662): “Patients enrolled in the placebo arm received SC injections matching active treatment to maintain the blind. To maintain the blind, all patients received two SC injections at weeks 0 and 4 and one SC injection at week 8, consisting of either briakinumab or matching placebo, depending on the treatment arm. In addition, each patient also received two SC injections biweekly, 3 days apart, week 0 through week 11, consisting of either etanercept or matching placebo, depending on the treatment arm.” Comment: probably done
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (p 662): “Patients enrolled in the placebo arm received SC injections matching active treatment to maintain the blind. To maintain the blind, all patients received two SC injections at weeks 0 and 4 and one SC injection at week 8, consisting of either briakinumab or matching placebo, depending on the treatment arm. In addition, each patient also received two SC injections biweekly, 3 days apart, week 0 through week 11, consisting of either etanercept or matching placebo, depending on the treatment arm.” Comment: probably done
Incomplete outcome data (attrition bias) All outcomes	Low risk	Randomly assigned 211, analysed 211 Management of missing data: Quote (p 663): “The primary efficacy analysis consisted of four comparisons performed in the intent‐to‐treat population (i.e. all randomised patients), …, Nonresponder imputation was used to handle missing data.” Comment: done
Selective reporting (reporting bias)	Low risk	Comment: the protocol for the study was available on ClinicalTrials.gov (NCT00710580). The pre‐specified outcomes and those mentioned in the methods section appeared to have been reported.