1. Validity of the EQ-5D in pemphigus vulgaris and foliaceus patients
Tamási B1, Brodszky V2, Péntek M2, Gulácsi L2, Hajdu K3,4, Sárdy M1, Szegedi A3,4, Bata-Csörgő Zs5, Kinyó Á6, Rencz F2,7
Department of Dermatology, Venereology and Dermatooncology, Faculty of Medicine, Semmelweis University, Mária u. 41., H-1085, Budapest, Hungary.
Department of Health Economics, Corvinus University of Budapest, Fővám tér 8. H-1093, Budapest, Hungary.
Departments of Dermatology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98., H-4032, Debrecen, Hungary.
Department of Dermatological Allergology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary.
Department of Dermatology and Allergology, Albert Szent-Györgyi Medical Centre, University of Szeged, Korányi fasor 6, H-6720, Szeged, Hungary.
Department of Dermatology, Venereology and Oncodermatology, University of Pécs, Akác u. 1., H-7632, Pécs, Hungary.
Hungarian Academy of Sciences, Premium Postdoctoral Research Program, Nádor u. 7, H-1051, Budapest, Hungary.
British Journal of Dermatology. DOI: /bjd.16883

2. Lead researcher Bela Tamasi, MD
Department of Dermatology, Venereology and Dermatooncology, Faculty of Medicine, Semmelweis University

3. Introduction What’s already known?
The detrimental impact of pemphigus on health-related quality of life has been reported in the literature.
No studies have used the EQ-5D questionnaire in pemphigus patients, so far.

4. Objective
Our purpose was to assess the quality of life and identify its most important predictors in pemphigus using the EQ-5D health status questionnaire.
We aimed to test the validity of EQ-5D in this patient population.

5. Methods
Between 2014 and 2017, a multicentre cross-sectional study was performed at four university dermatology departments in Hungary.
Hungarian versions of validated outcome measures were used to assess general (EQ-5D-5L and EQ VAS) and skin-specific quality of life (Dermatology Life Quality Index, DLQI), disease severity (Autoimmune Bullous Skin Disorder Intensity Score), and pain (visual analogue scale, VAS).
The value set for England developed by Devlin et al. was applied in this study to derive EQ-5D index scores, whereby utilities range between and 1.

6. Results(1)
Our purpose was to assess the quality of life and identify its most important predictors in pemphigus using the EQ-5D health status questionnaire.
We aimed to test the validity of EQ-5D in this patient population.

7. Results(2): Distribution of responses to the five dimensions of the EQ-5D questionnaire

8. Results (3): Convergent validity of the EQ-5D and EQ VAS
Variables
EQ-5D-5L
( to 1)
EQ VAS
EQ VAS (0-100)
0.607 -
DLQI (0-30)
-0.619
-0.463
ABSIS (0-206)
-0.396
-0.163*
Average pain intensity VAS§ (0-100)
-0.593
-0.338
Worst pain intensity VAS§ (0-100)
-0.499
-0.298
Age (years)
-0.252
-0.194
Disease duration (years)
0.182*
0.004*
*not significant (p≥0.05) § in the past 3 months

9. Discussion
Pemphigus has a large negative effect of quality of life as assessed by the EQ-5D questionnaire.
The EQ-5D allows measuring the health gains associated with high- cost but very effective drugs, such as rituximab.
It is very likely that, similarly to psoriasis, the EQ-5D will become the major tool to obtain quality-of-life data in economic evaluations of pemphigus treatments.

10. Conclusions What does this study add?
This is the first study employing the EQ-5D questionnaire in pemphigus.
The EQ-5D is a valid instrument for the evaluation of health- related quality of life in pemphigus vulgaris and foliaceus.
Pain intensity, mucocutaneous involvement and comorbidities are important predictors of quality of life.
The EQ-5D might help to better understand the health loss from pemphigus.

11. Research team
Corvinus University of Budapest, Department of Health Economics
Dr Fanni Rencz
Dr Valentin Brodszky
Prof László Gulácsi
Prof Márta Péntek
Semmelweis University, Department of Dermatology, Venereology and Dermatooncology
Dr. Bela Tamasi
Prof Miklós Sárdy
University of Debrecen, Departments of Dermatology
Prof Andrea Szegedi
Dr Krisztina Hajdu
Department of Dermatology and Allergology, Albert Szent-Györgyi Medical Centre, University of Szeged
Prof Zsuzsa Bata-Csörgő
Department of Dermatology, Venereology and Oncodermatology, University of Pécs
Dr Ágnes Kinyó

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