A randomized, double-blind study randomized 109 psoriasis patients to either a high (40% incremental doses) or low (20% incremental doses) dose narrowband UVB (NBUVB) regimen, given three times weekly. The Psoriasis Area and Severity Index (PASI) was measured at baseline and at every 4-week control visit. Treatment was discontinued in cases of clearance (90% reduction in PASI from baseline). No significant differences were found in the numbers of patients achieving clearance between the two NBUVB groups. Three months after cessation of treatment, a significantly better outcome was seen in the high-dose group and these patients had required fewer treatments than the low-dose group. This finding has important cost-benefit implications (Kleinpenning, M.M. et ...