Health-Related Quality of Life for Eating Disorders questionnaire version-2 was responsive 1-year after initial assessment Carlota Las Hayas a, * , Jose M. Quintana a , Jesus A. Padierna b , Amaia Bilbao c , Pedro Mun ˜oz d , E. Francis Cook e a Research Unit, Galdakao Hospital, Galdakao, Bizkaia, Spain b Department of Psychiatry, Galdakao Hospital, Galdakao, Bizkaia, Spain c The Basque Foundation for Health Innovation and Research (BIOEF) Plaza Asua, Bizkaia, Spain d Department of Psychiatry, Ortuella Mental Health Center, Ortuella, Bizkaia, Spain e Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA Accepted 2 October 2006 Abstract Objectives: To assess the responsiveness of the Health-Related Quality of Life for Eating Disorders questionnaire version-2 (HeRQo- LEDv2) and present the psychometric characteristics of a new binge domain. Study Design and Setting: Patients with an eating disorder completed the HeRQoLEDv2, the Eating Attitudes Test-26, Short Form Health Survey-12, and two items from the Eating Disorder Inventory-2, at baseline and after 1 year. At the second assessment, patients completed the HeRQoLEDv2, as part of the battery of tests, along with health transitional questions. Validity and reliability analyses of the new binge domain were performed. Responsiveness was evaluated using distributional and anchor-based approaches, comparison of mean changes, mean change correlations, the minimal detectable change (MDC) at the individual and group level, and the minimal impor- tant difference (MID). Results: Items in the binge domain loaded above 0.40. Cronbach alpha was 0.82. Regarding responsiveness, the mean changes detected by the HeRQoLEDv2 correlated above 0.30 with the criterion measures. Patients who reported improvement showed significant changes, and effect sizes above 0.30. The MDC 90%ind was larger than the MID. Conclusion: The HeRQoLEDv2 includes the new binge domain. It responded to change at the group level. Further research regarding the MID is needed. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Questionnaires; Reproducibility of results; Health related quality of life; Eating disorders; Minimal important difference; Health status indicators 1. Introduction The Health-Related Quality of Life for Eating Disorders Questionnaire (HeRQoLED) [1] is a self-administered questionnaire that provides a profile of the influence that the Eating Disorder (ED) has in different domains that compose the quality of life of an individual with ED. It is a Health-Related Quality of Life (HRQL) specific instru- ment for individuals with any ED subtype (Anorexia Nerv- osa, Bulimia Nervosa, and Eating Disorders Not Otherwise Specified). In an earlier study [1], the validity and reliabil- ity were assessed with satisfactory results. The instrument also showed sensitivity to different populations, since it yielded significantly lower scores for a sample of female university students than for a group of patients with an ED. The HeRQoLED, however, has two issues that must be addressed. First, the previous binge domain that was part of the questionnaire did not meet the necessary psychomet- ric criteria. This implies a shortcoming in the HRQL con- tent because bingeing/purging behaviors severely affect patients’ HRQL. Second, the responsiveness of the HeR- QoLED questionnaire has not been studied. There are cur- rently a variety of measurement definitions and statistics to study responsiveness [2,3]. We defined responsiveness in our research as ‘‘the ability of an instrument to detect real changes in the concept being measured’’ [4]. Because the HeRQoLED is designed to be useful as an outcome and evaluative measure, it is essential to determine if it can de- tect changes that occur naturally or are due to clinical inter- vention in the patient over time. The aims of this study were to examine the responsiveness of the HeRQoLED using distributional and anchor-based approaches [3,5e8]. Among other distributional-based * Corresponding author. Tel.: +34 94 400 7105; fax: +34 94 400 7132. E-mail address: uinves3@hgda.osakidetza.net (C. Las Hayas). 0895-4356/07/$ e see front matter Ó 2007 Elsevier Inc. All rights reserved. doi: 10.1016/j.jclinepi.2006.10.004 Journal of Clinical Epidemiology 60 (2007) 825e833