Proposal of a new scoring formula for the DLQI in psoriasis

Abstract

Summary Psoriasis is a common skin disease affecting approximately 2% of the population. Psoriasis can have a negative impact on patients’ everyday activities and wellbeing. Dermatology Life Quality Index (DLQI) is a widely used measure to assess quality of life in patients with psoriasis. It consists of 10 questions covering symptoms and feelings, daily activities, leisure, work and school, personal relationships and treatment. Each question is scored as follows: ‘not at all’=0, ‘a little’=1, ‘a lot’=2 and ‘very much’=3. However, certain questions of the DLQI such as sports, sexual difficulties and working/studying are not relevant to every patient. As ‘not relevant’ responses are scored as if the item of the questionnaire had no impact on patients’ life at all (=0), they may artificially improve patients’ quality of life scores. For these patients, despite having severe psoriasis, it is more difficult to fulfil the DLQI threshold required by clinical guidelines to become candidates for stronger, systemic treatments such as biologics. This study, from Hungary, involved 242 patients with psoriasis. The authors developed a new scoring for the DLQI questionnaire, namely the DLQI‐R that corrects for the bias in the ‘not relevant’ response option, and proved its validity (i.e. that it works). The DLQI‐R scoring formula eliminates the items marked as ‘not relevant’ while increasing the weight of the relevant items in the total score of the questionnaire. It primarily strives to provide fair access to systemic treatments for psoriasis patients who cannot comply with the DLQI criteria in treatment guidelines because certain items of the questionnaire are simply not relevant to them.

Evaluation of the Dermatology Life Quality Index scoring modification, the DLQI‐R score, in two independent populations

“…Recently, Rencz et al . proposed a scoring modification for the DLQI, the DLQI‐R score, in which the traditional DLQI score is multiplied by a conversion factor that increases with the number of NRRs . Their reanalysis of 242 patients involved in two cross‐sectional surveys conducted in Hungary showed the DLQI‐R had a moderate correlation with Psoriasis Area and Severity Index (PASI) scores and EQ‐5D‐3L index values, with higher correlation coefficients than the DLQI score.…”

“…This study aimed to validate the DLQI‐R scoring modification proposed by Rencz et al . in an independent population of patients with psoriasis.…”

Time to revise the Dermatology Life Quality Index scoring in psoriasis treatment guidelines

“…Before 2017, no studies have investigated the proportion of psoriasis patients ticking NRRs, and very few studies reported on the rate of NRRs per each DLQI item. [7][8][9] Recently, however, four studies originating from Hungary, 10,11 Germany 12 and the United States 13 dealt with this issue. Table 1 shows the most important findings from these four analyses on NRRs.…”

“…A promising solution to address the issue of NRRs is a recently developed new scoring, the DLQI-R (where R refers to 'relevant'). 11 This scoring adjusts the total DLQI score to the number of NRRs and resolves the bias from NRRs. Construct validity of the DLQI-R scoring with PASI, EQ-5D-3L and EQ VAS was indicated by two independent studies in Hungary and the United States.…”

“…Construct validity of the DLQI-R scoring with PASI, EQ-5D-3L and EQ VAS was indicated by two independent studies in Hungary and the United States. 11,13 Switching to DLQI-R would be a way to keep on using the DLQI-a widely known and accepted outcome measure-while fixing the apparent bias of NRRs. Nevertheless, undertaking a series of methodological research to confirm the favourable psychometric properties of the DLQI-R is needed.…”