Goldfarb 1988.

Study characteristics
Methods	RCT, placebo‐controlled, double‐blind Date of study: not stated Location: not stated
Participants	Randomised: 38 participants (mean age 45 ‐ 48 years, 31 male) Inclusion criteria BSA 10 ‐ 70 Exclusion criteria No women of childbearing potential Dropouts and withdrawals 0/38 (0%)
Interventions	Intervention A. Acitretin (n = 10), orally, 10 ‐ 25 mg/day, 8 weeks B. Acitretin (n = 16), orally, 50 ‐ 75 mg/day, 8 weeks Control intervention C. Placebo (n = 12), orally, daily, 8 weeks
Outcomes	Assessments at 8 weeks Primary outcomes of the trial Not stated Outcomes of the trial Percentage of skin involvement with psoriasis Overall scaling, erythema, thickness, and global extent of the disease on a 0 through 6 scale Improvement range from worse/unchanged/fair/good/excellent AEs
Notes	Funding sources, quote (p 655): "Supported in part by Hoffman‐La Roche Inc., Nutley, NJ, and the Babcock Dermatologic Endowment" Declarations of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (p 656): "21 patients were randomly and equally divided into 4 groups" Comment: no description of the method used to generate the sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote (p 656): "21 patients were randomly and equally divided into 4 groups" Comment: no description of the method used to guarantee allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote (p 656): "we have studied 38 patients in a double‐blind fashion" Comment: visible side effect of acitretin
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote (p 656): "we have studied 38 patients in a double‐blind fashion" Comment: visible side effect of acitretin
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Randomly assigned 38, analysed 38 No mention of how the missing data were managed
Selective reporting (reporting bias)	Unclear risk	Comment: no protocol was available. The prespecified outcomes mentioned in the Methods section appeared to have been reported