PIECE 2016.

Study characteristics
Methods	RCT, active‐controlled Date of study: April 2009 and June 2011 Location: 5 centres in The Netherlands
Participants	Randomised: 50 participants Inclusion criteria 18 ‐ 75 years Moderate‐to‐severe chronic plaque type psoriasis defined as PASI ≥ 10 and/or BSA ≥ 10 and/or PASI ≥ 8 plus a Skindex‐29 score ≥ 35 Patients must have had unsuccessful treatment with or were contraindicated and/or intolerant of UV therapy, and methotrexate or cyclosporin Exclusion criteria Pregnant, breastfeeding Malignancy in the previous 10 years Active/chronic infections including TB Demyelinating disease Congestive heart failure Severe liver function disorders > 2 times and/or kidney function disorders > 1.5 times upper limit of the parameters Dropouts and withdrawals 15/50 (30%) False inclusion: infliximab (0), etanercept (2) AEs: infliximab (1), etanercept (3) Injection fear: infliximab (0), etanercept (1) Switch to etanercept: infliximab (3), etanercept (not applicable) Switch to infliximab: infliximab (not applicable), etanercept (3) No response: infliximab (0), etanercept (1) Lost to follow‐up: infliximab (1), etanercept (0)
Interventions	Intervention (n = 48) A. Infliximab (n = 25), IV, 5 mg/kg, weeks 0, 2, 6, 15, 22 Control intervention B. Etanercept (n = 23), SC, 50 mg twice weekly
Outcomes	Assessment at 24 weeks Primary outcomes of the trial PASI 75 Secondary outcomes of the trial QoL scale, Global assessment, treatment satisfaction
Notes	Funding source quote (p 1): "study was funded by a program grant from the Netherlands Organization for Scientific Research‐Medical Sciences (NWO‐MW; project 152001006)." Declaration of interest: "A.C.Q. de Vries: none reported; H.B. Thio: has been a consultant and invited speaker for Biogen/Idec, Janssen, Abbvie, Pfizer, MSD, Leopharma, Teva and Novartis. He has received educational grants from Abbvie, Janssen, Pfizer and Biogen/Idec.; W.J.A. de Kort: medical advisor for Novartis; B.C. Opmeer: none reported; H.M. van der Stok: Involved in performing clinical trials with Abbvie, Pfizer, Novartis, Janssen, BioClinic, AMGEN and LeoPharma.; E.M.G.J. de Jong: received research grants for the independent research fund of the department of dermatology of University Medical Centre St Radboud Nijmegen, the Netherlands from AbbVie, Pfizer, and Janssen. Has acted as consultant and/or paid speaker for and/or participated in research sponsored by companies that manufacture drugs used for the treatment of psoriasis including AbbVie, Janssen, MSD, and Pfizer.; B. Horvath: Unrestricted Educational Grant from AbbVie, IIS Studies by Janssen, AbbVie, Performing clinical trial Novartis, Solenne B.V., Consultancies: Abbvie, Janssen, Philips, Galderma.; J.J.V.Busschbach: none reported; T.E.C. Nijsten: received research grants for the independent research fund of the department of dermatology of Erasmus MC, Rotterdam, the Netherlands from AbbVie, Leo Pharma, MSD, Pfizer, and Janssen. Has acted as consultant and/or paid speaker for and/or participated in research sponsored by companies that manufacture drugs used for the treatment of psoriasis including AbbVie, Leo Pharma, Galderma, Janssen, MSD, and Pfizer. ; Ph.I. Spuls: consultancies in the past for Leopharma, AbbVie and Novartis. In the past an independent research grant from Schering Plough and from Leopharma. Involved in performing clinical trials with many pharmaceutical industries that manufacture drugs used for the treatment of psoriasis."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote (pp 4 & 8): “...was a multi‐centre, single‐blind, investigator initiated, randomised controlled trial comparing infliximab and etanercept in the treatment of moderate to severe chronic plaque type psoriasis... Adequate generation of an unpredictable allocation sequence and concealment of allocation was achieved by using a secure online internet facility (the TEN‐ALEA Clinical Trial Data Management System, provided by the Trans European Network http://www.tenalea.com/) performed in the coordinating centre by the main investigators. The sequence was generated in random block sizes of two and four to ensure it was unknown and not predictable by the investigators involved in randomising participants." Comment: done
Allocation concealment (selection bias)	Low risk	Quote (pp 4 & 8): “...was a multi‐centre, single‐blind, investigator initiated, randomised controlled trial comparing infliximab and etanercept in the treatment of moderate to severe chronic plaque type psoriasis... Adequate generation of an unpredictable allocation sequence and concealment of allocation was achieved by using a secure online internet facility (the TEN‐ALEA Clinical Trial Data Management System, provided by the Trans European Network http://www.tenalea.com/) performed in the coordinating centre by the main investigators. The sequence was generated in random block sizes of two and four to ensure it was unknown and not predictable by the investigators involved in randomising participants." Comment: done
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote (pp 4 & 8): “...was a multi‐centre, single‐blind, investigator initiated, randomised controlled trial comparing infliximab and etanercept in the treatment of moderate to severe chronic plaque type psoriasis..." Comment: no blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote (p 8): "Efficacy outcomes were carried out by trained assessors who were blinded to treatment allocation." Comment: no clear description of measures taken to guarantee the blinding of investigators
Incomplete outcome data (attrition bias) All outcomes	Low risk	Randomly assigned 50, analysed 48 Quote (pp 8 & 9): "Missing data on primary endpoint were imputed using last observation carried forward. Analyses were carried out according to intention‐to‐treat (ITT) principle, apart from the longer term data where a per protocol analysis (PPA) was performed" Comment: probably done
Selective reporting (reporting bias)	Unclear risk	The trial was prospectively registered on the Dutch Trial Register: www.trialregister.nl/trialreg/index.asp; NTR 1559 The prespecified outcomes mentioned in the Methods section appeared to have been reported