Psychometric validation of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Endometrial Cancer Module (EORTC QLQ-EN24)

Abstract

Aim A validation study was conducted to evaluate the psychometric properties of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Endometrial Cancer Module (EORTC QLQ-EN24). This module was designed to assess disease and treatment specific aspects of the quality of life (QoL) of patients with endometrial cancer. Methods Two hundred and sixty-eight women with endometrial cancer were recruited in different phases of treatment: after pelvic surgery (Group 1); during adjuvant chemotherapy and/or radiotherapy (Group 2); after completion of treatment (Group 3). Patients completed the EORTC QLQ-C30, the endometrial cancer module and a short debriefing questionnaire. Results Multi-trait scaling analyses confirmed the hypothesised scale structure of the QLQ-EN24. Internal consistency reliability was good with Cronbach’s alpha coefficients ranging from 0.74 to 0.86 (lymphoedema 0.80, urological symptoms 0.75, gastrointestinal symptoms 0.74, body image problems 0.86 and sexual/vaginal problems 0.86). Convergent and discriminant validity did not show any scaling errors for the subscales. The QLQ-EN24 module discriminated well between clinically different groups of patients. All items exhibited a high completion rate with less than 2% missing values except for the sexuality items (19%). Conclusion The validation study supports the reliability, the convergent and divergent validity of the EORTC QLQ-EN24. This newly developed QLQ-EN24 module is a useful instrument for the assessment of the QoL in patients treated for endometrial cancer in clinical trials.