Background: Psoriasis affects patients both physically and psychologically.
Objectives: To investigate the effect of comorbidities on health-related quality of life (HRQoL) and to determine whether infliximab improved HRQoL in the presence of these conditions.
Methods: In this multicentre, double-blind study, 835 patients with moderate-to-severe plaque psoriasis were randomized to receive infliximab 3 or 5 mg kg(-1) or placebo at weeks 0, 2 and 6. Infliximab-treated patients were re-randomized at week 14 to receive the same treatment every 8 weeks or as needed through week 46; placebo patients crossed over to infliximab 5 mg kg(-1) at week 16. Disease severity (Psoriasis Area and Severity Index, PASI) and HRQoL (Dermatology Life Quality Index, DLQI; 36-item Short-Form Health Survey, SF-36) were measured at various time points. The effect of patient comorbidities on baseline HRQoL was assessed using multiple regression models. The impact of key comorbidities on infliximab treatment effect was also assessed.
Results: Disease severity (PASI), depression and psoriatic arthritis (PsA) were predictors of poor baseline HRQoL. At week 10, infliximab 3 and 5 mg kg(-1) significantly improved physical and mental health dimensions of the SF-36 and the DLQI (all P < 0.001). Consistent improvement in HRQoL with infliximab treatment was observed regardless of baseline patient characteristics or comorbidities. Through week 50, HRQoL and PASI scores were most improved with infliximab 5 mg kg(-1) administered every 8 weeks.
Conclusions: Disease severity, depression and PsA were significant predictors of poor HRQoL. Infliximab significantly improved HRQoL, regardless of these characteristics.