Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Symptom improvement
Systematic review 5-armed trial	38 people Data from 1 RCT	Response rate with acitretin (10 mg, 25 mg, 50 mg, or 75 mg) with placebo	Reported no significant difference between acitretin (any dose) and placebo RCT was underpowered		Not significant
Systematic review 4-armed trial	80 people with severe psoriasis Data from 1 RCT	Proportion of people who achieved a 75% or greater decrease in Psoriasis Area and Severity Index (PASI) score, or a PASI score of <8 8 weeks 12/20 (60%) with acitretin 25 mg 5/20 (25%) with placebo	ARI 35% 95% CI 6% to 64%	Effect size not calculated	acitretin 25 mg
Systematic review 4-armed trial	80 people with severe psoriasis Data from 1 RCT	Proportion of people who achieved a 75% or greater decrease in PASI, or a PASI score of <8 8 weeks 14/20 (70%) with acitretin 50 mg 5/20 (25%) with placebo	ARI 45% 95% CI 17% to 73%	Effect size not calculated	acitretin 50 mg
Systematic review 4-armed trial	80 people with severe psoriasis Data from 1 RCT	Proportion of people achieving a 75% or greater decrease in PASI score, or a PASI score of <8 8 weeks 8/20 (40%) with acitretin 10 mg 5/20 (25%) with placebo	ARI +15% 95% CI –14% to +44%		Not significant