Wing Yan Yuen, Department of Dermatology, University Medical Center Groningen, Hanzeplein 1, NL-9700 RB Groningen, The Netherlands. E-mail: w.y.yuen@umcg.nl Epidermolysis bullosa (EB) consists of a spectrum of heritable trauma-induced blistering diseases of skin and mucous membranes (1). Many subtypes exist, and their clinical severity is variable, ranging from an occasional palmoplantar blister to childhood lethality (1). The health-related quality of life (HRQoL) is the impact of a disease on the physical, psychological, and social health of a patient (2). Defining HRQoL in EB patients is important in patient care and management (3). Furthermore, in recent years more focus has been placed on finding specific treatments for EB and measuring HRQoL can help in assessing the efficacy of these new treatment modalities (4, 5). Also, measuring and comparing HRQoL to other diseases can help assign funding to this rather unknown and rare disorder (4, 6). Measuring HRQoL is complicated by the wide range of phenotypes in EB, which all have their own clinical severity (3). Several studies have focused on qualitatively describing the impact of EB on patients' lives (7-11). Quantitative measurement of HRQoL has been performed using both generic and dermatology-specific instruments in EB patients (6, 12-15). However, due to ceiling effects and content validity issues of these instruments, the accuracy of the measurements is questionable. It has been hypothesised that, especially in the more severe EB subtypes, there has been an overestimation of the HRQoL (3). To overcome these problems, Frew et al. (3) developed and validated an EB-specific HRQoL measurement tool for older children and adults that can be used across all EB subtypes, called the QOLEB (quality of life in EB). Translation of the QOLEB, which was created and validated in English in Australia, to other cultures and languages may provide reliable comparisons of HRQoL in EB and the efficacy of clinical interventions across different countries (3). The aim of this study was to develop a validated and reliable QOLEB in Dutch, and to assess HRQoL in Dutch EB patients.
MATERIALS AND METHODSThis study was performed at the Center for Blistering Diseases at the University Medical Center Groningen, which is the single national referral centre for EB in the Netherlands. Ethical approval was granted by the Medical Ethical Committee of the University Medical Center Groningen in the Netherlands. A signed consent form was obtained from all participating patients.
Study measurement toolsThe English QOLEB is a validated and reliable adult EBspecific HRQoL tool consisting of a 17-item questionnaire, and it was developed by 2 of the authors (JWF and DFM) (3). The QOLEB measures 2 factors: functioning (questions 1-7, 9-10, 12-13, 15) and emotions (question 8, 11, 14, 16-17). For each question 4 optional answers exist that are scored from 0 to 3 points, in which a higher score represents a worse HRQoL. The functioning scale ranged from 0-36, the emotions scale from 0-15, and the ove...