Association between eq-5d and dermatology life quality index (dlqi) in patients with chronic hand eczema

INTRODUCTION & OBJECTIVES: HRQoL is often impaired in patients with skin diseases but it is often assessed with different instruments, generating data not directly comparable or not suitable to estimate utility. Assessing the association between HRQoL measures obtained with different instruments could be useful to obtain more complete data. The dermatology life quality index (DLQI) is a condition-specific questionnaire widely used to assess HRQoL in subjects with skin diseases. We aimed to estimate the association between EQ-5D VAS and utility score with the DLQI summary score (max 30 and min 0; higher score corresponds to more impaired quality of life) in patients with severe CHE and refractory to therapy with topical potent corticosteroids. MATERIAL & METHODS: within a naturalistic, multicentre cost-of-illness study; patients aged ≥18 years, consecutively accessing at the participating centres, completed the EQ-5D and DLQI questionnaires during the enrolment visit. Individual patient utility was estimated from EQ-5D responses using the standard UK scoring algorithm. A multivariable linear regression model was built to estimate the association between the EQ-5D VAS and utility score with the DLQI summary score, adjusted for age and gender. The bootstrap resampling was used to calculate standard errors and 95% confidence intervals. RESULTS: 104 patients (mean age+SD=44.5+15.0, 39.4% male) were enrolled. DLQI mean+SD summary score was 11.3+6.3, EQ-5D VAS mean+SD=60.4+23.3 and EQ-5D utility mean+SD=0.50+0.31. EQ-5D VAS and utility showed a linear negative relationship with DLQI summary score. One point rise in DLQI was associated with a EQ-5D VAS decrease of 1.84 (SE=0.34; 95%CI=-2.52,-1.16; adjusted R2=0.238) and a utility index decrease of 0.025 (SE=0.005; 95%CI=-0.035,-0.014; adjusted R2=0.232) in utility CONCLUSIONS: DLQI summary score is significantly associated with the EQ-5D VAS and utility index. Our results could be useful to derive EQ-5D information from DLQI data, to perform economic evaluations targeted to patients with severe CHE refractory to therapy with topical potent corticosteroids.