Yang 2012.

Study characteristics
Methods	RCT, placebo‐controlled, double‐blind Date of study: February 2009 ‐ February 2010 Location: 9 centres in China
Participants	Randomised: 129 participants (mean age 39 years (infliximab) and 40 years (placebo), 95 male) Inclusion criteria Participants with moderate‐severe psoriasis (PASI ≥ 12, BSA ≥ 10), age 18 ‐ 65 years Had a diagnosis of plaque psoriasis for at least 6 months Had failed to respond to conventional systemic treatment of psoriasis including: ciclosporin, methotrexate, or acitretin as previous treatment Exclusion criteria Non‐plaque forms of psoriasis A history of a chronic infectious disease or opportunistic infection A serious infection within 2 months of enrolment Active or latent TB Pregnancy or planned pregnancy within 12 months of enrolment A history of lymphoproliferative disease An active malignancy or history of malignancy within 5 years Dropouts and withdrawals 2/129 (1.55%): infliximab group (1), placebo group (1) Withdrawal of informed consent: infliximab group (0), placebo group (1) Adverse event: infliximab group (1), placebo group (0)
Interventions	Intervention A. Infliximab (n = 84), IV, 5 mg/kg, weeks 0, 2, 6, 14, 22; 22 weeks Control intervention B. Placebo (n = 45), IV, weeks 0, 2, 6 then infliximab 5 mg/kg weeks 10, 12, 16
Outcomes	Assessments at 10 weeks Primary outcomes of the trial PASI 75 Secondary outcomes of the trial PGA DLQI
Notes	Funding source: not stated Declarations of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (p 1846): "This randomised, double‐blind, placebo controlled trial... Eligible patients were randomly assigned in a 1:2 ratio to the placebo and infliximab" Comment: no description of the method used to guarantee random sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote (p 1846): "This randomised, double‐blind, placebo controlled trial... Eligible patients were randomly assigned in a 1:2 ratio to the placebo and infliximab" Comment: no description of the method used to guarantee allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote (p 1846): "This randomised, double‐blind, placebo controlled trial... Eligible patients were randomly assigned in a 1:2 ratio to the placebo and infliximab... Infliximab 5 mg/kg or placebo was administered by intravenous drip infusion over a period of at least 2 hours on the starting day of treatment (week 0) and at weeks 2 and 6 (induction)". Comment: probably done
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (p 1846): "This randomised, double‐blind, placebo controlled trial... Eligible patients were randomly assigned in a 1:2 ratio to the placebo and infliximab... Infliximab 5 mg/kg or placebo was administered by intravenous drip infusion over a period of at least 2 hours on the starting day of treatment (week 0) and at weeks 2 and 6 (induction)". Comment: probably done
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Randomly assigned 129, 129 Analysed Quote: "In the primary efficacy analysis, data from all randomised subjects were analysed according to their assigned treatment group..." Comment: no description of the method used to manage the missing data
Selective reporting (reporting bias)	Unclear risk	Comment: no protocol was available. The prespecified outcomes mentioned in the Methods section appeared to have been reported