Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Psoriasis severity
RCT	113 people with mild to moderate psoriasis	Clearance rates 40/58 (69%) with twice-weekly UVB 44/55 (80%) with 3 times-weekly UVB	P = 0.21		Not significant
RCT	113 people with mild to moderate psoriasis	Mean time to clearance 88 days with twice-weekly UVB 58 days with 3 times-weekly UVB	P <0.0001	Effect size not calculated	3 times-weekly UVB