Background: As moderate to severe psoriasis is a systemic disease with large effects on health related quality of life (HRQOL) generic measures that include overall health, not only skin involvement, are necessary. The knowledge about the relationship between the generic preference-based EQ-5D and dermatology-specific measures in psoriasis is limited.
Objective: The objective was to analyse EQ-5D, the Dermatology Life Quality Index (DLQI) and Psoriasis Area and Severity Index (PASI) in patients with moderate to severe psoriasis in Swedish clinical practice by demographic characteristics, to compare EQ-5D among patients to Swedish population values, and to analyse the relationships between EQ-5D, DLQI and PASI.
Methods: This observational cohort study was based on PsoReg, the Swedish National Registry for Systemic Treatment of Psoriasis. EQ-5D among psoriasis patients was compared to a defined general population in Sweden, retrieved from a previous study. Relationships between measures were examined with correlation tests and regression analysis.
Results: 2450 patients (men n=1479, women n=971) were included. Median EQ-5D, DLQI and PASI was 0.769, 4 and 4.7, respectively. Psoriasis patients had a significantly lower EQ-5D compared to the defined general population. EQ-5D correlated moderately with DLQI (-0.55) and weakly with PASI (-0.25) (p<0.001).
Conclusions: When assessing psoriasis treatments and making decisions about treatment guidelines and resource allocation, EQ-5D, DLQI and PASI provide a useful set of complementary tools, answering to different needs. If EQ-5D is not included in the original trial the second best option in cost-effectiveness studies is to use mapping between DLQI and EQ-5D.
Wiley-Blackwell, 2012. Vol. 166, no 4, 797-802 p.