Background/objectives: Patients with psoriasis experience higher rates of depression, anxiety and suicidal ideation than the general population. With effective treatment, there is evidence that with the initial decrease in the psoriasis area and severity index (PASI) score, patients' quality of life (QoL), measured by the dermatology life quality index (DLQI) improves. However, to date, there have been no studies demonstrating that patients' QoL remains improved. We investigated the association between the DLQI and PASI of patients with psoriasis on biologic agents for an extended period of time of up to 6.5 years.
Methods: The data for this longitudinal, retrospective study was collected from a large tertiary teaching hospital in South Australia. Data was collected from all patients with psoriasis who had been on biologic agents for 2 or more years (n = 54).
Results: PASI and DLQI were highly correlated over all time points (ρ = 0.50), P < 0.001. DLQI scores significantly decreased by 0.8 (95% CI: 0.30, 1.26) units per year from 12 months to 6.5 years, P = 0.002. After 12 months, PASI scores declined by 0.19 (95% CI: 0.13, 0.52) units per year, P = 0.24.
Conclusion: This study demonstrates that DLQI and PASI remain low after 12 months, and, in fact, both gradually decline further with time. Patients on biologic agents for prolonged periods maintained their improvement in QoL for up to 6.5 years.
Keywords: DLQI; PASI; biologic immune modifying agent; biologics; dermatology life quality index; durable DLQI; health-related quality of life; psoriasis; psoriasis area and severity index; quality of life.
© 2015 The Australasian College of Dermatologists.