Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
RCT	46 people with 75% reduction in initial Psoriasis Area and Severity Index [PASI] score for plaque psoriasis (complete trial included 42 people with guttate or plaque psoriasis) Subgroup analysis	Adverse effects with 12 sessions of narrowband UVB over 2 months with no maintenance treatment Absolute results not reported	The RCT was small, and randomised using toss of a coin. It is likely to have been underpowered to detect clinically important differences between groups