A retrospective analysis of a phase III infliximab (IFX) trial assessed whether currently established nail severity and health-related quality of life (HRQoL) measures adequately reflect disease impact on quality of life. The outcome measures evaluated comprised the Nail Area and Psoriasis Severity Index (NAPSI), Number of Nails Affected (NNAIL), Dermatology Life Quality Index (DLQI), the Short Form-36 (SF-36)-Mental Component Scale (MCS) and Physical Component Scale (PCS) at baseline and week 50. No significant correlations between baseline NAPSI and DLQI, SF-36 MCS or PCS were seen. Moreover, no clinically significant correlation between NNAIL and HRQoL measures at baseline were seen. Infliximab significantly improved NAPSI, NNAIL, DLQI and SF-36 MCS and PCS indices through ...