Mapping DLQI on EQ-5D in psoriasis: transformation of skin-specific health-related quality of life into utilities

Abstract

In many countries, utility measures are required for allocation decisions. Unlike the EuroQoL-5D (EQ-5D), the dermatology life quality index (DLQI) has not been developed for the derivation of utilities. Purpose of this study was to develop and test an algorithm for the transformation of DLQI scores into utilities. Pre-existing data of two cross-sectional studies (for development, n = 1,511; for cross-validation n = 2,009) of German psoriasis patients were reanalyzed. Both EQ-5D global score and EQ-5D visual analogue scale (VAS) were used as utility measures. Correlations were computed to identify predictors of EQ-5D utilities. Linear stepwise regressions were conducted using DLQI and further possible predictors to find the optimal mapping algorithm. Using only DLQI as predictor resulted in coefficients of determination of r (2) = 0.235 (EQ-5D global score) and r (2) = 0.242 (EQ-5D VAS). In the final algorithm, seven predictors were included which correctly predicted EQ-5D VAS for 60.4 % (development database) and 60.8 % of all patients (cross-validation database) within a range of ±15 units. The algorithm explained 31.3 % of the EQ-5D variance in the development database and 26.8 % in the cross-validation database. In conclusion, mapping of DLQI on EQ-5D in psoriasis patients has severe limitations in validity and clinical relevance.

Exploring the relationship between EQ-5D, DLQI and PASI, and mapping EQ-5D utilities: a cross-sectional study in psoriasis from Hungary

“…Our model 471 is in line with these two bivariate algorithms, the constant 472 term is about 0.8 and one point increase in DLQI is 473 expected to result in a reduction of 0.02 point in EQ-5D. 474 A study from Germany including 1,511 patients per-475 formed by Blome et al [9] could predict 24.2 % of the 476 variability of EQ VAS with the following mapping algo-477 rithm: EQ VAS = 77.367 -1.493*DLQI (p \ 0.001).…”

“…Two observational studies reported a weak correlation 367 between PASI and EQ-5D (r = -0.17, -0.25) [8,9]. In 368 contrast, we noted moderate correlation (r = -0.43) 369 between these two measures.…”

“…112 Prior mapping studies could explain only 27-31.3 % of the 113 variance of EQ-5D [8][9][10]. Consequently, almost 70 % of 114 the possible predictors of EQ-5D in psoriasis has still 115 remained hidden.…”

Quality of life and dermatovenerology

“…Childrens dermatology life quality index) upitnik prilagođen deci, uzrasta od 4 do 16 godina, inače sličan DLQI; EuroQoL EQ-5D (engl. EuroQoL EQ-5D (Quality of Life Scale-EQ-5D) opšti zdravstveni upitnik, koji se koristi za merenje QoL mnogih bolesti, uključujući i psorijazu; QUAVIDERM (Qualita di Vita Italiana in dermatologia); PLSI (engl.Psoriasis Life Stress Invertory); SPI (engl.Salford Psoriasis Index); kao i: Psoriasis Disability Scale i Psoriasis Stressor Scale [1,4,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Da je ispitavanje QoL I dalje veoma aktuelno u stručnim krugovima potvrdiće podatak da ukucavanjem reči kvalitet života (quality of life) na Google pretraživaču pokazuje 1.160.000.000 rezultata, a na Pub Med-u: 221698; ali se nudi veći broj pojmova, pa se može pretpostaviti da je sumarno broj mnogo veći; npr.…”

Centralised Biological Therapy Registry for Moderate to Severe Plaque Psoriasis – Overview and Methodology

“…-Primary objectives 1) long-term efficacy 2) long-term safety -Secondary objectives 1) efficacy and safety in relation to the comorbidities 2) patient quality of life 3) predictors of treatment outcomes 4) disease severity progress and therapeutic modality sequence since first diagnosis The cost effectiveness analysis in terms of quality adjusted life year (QALY) parameter is not in a scope, but in case of need Dermatology Life Quality Index (DLQI) questionnaire data can be extrapolated to Health-related quality of life questionnaire (EQ-5D) [33,34,35].…”