IntroductionEarly guidelines for minimally important differences (MIDs) for the EORTC QLQ-C30 proposed ≥10 points change as clinically meaningful for all scales. Increasing evidence that MIDs can... Show moreIntroductionEarly guidelines for minimally important differences (MIDs) for the EORTC QLQ-C30 proposed ≥10 points change as clinically meaningful for all scales. Increasing evidence that MIDs can vary by scale, direction of change, cancer type and estimation method has raised doubt about a single global standard. This paper identifies MID patterns for interpreting group-level change in EORTC QLQ-C30 scores across nine cancer types.MethodsData were obtained from 21 published EORTC Phase III trials that enroled 13,015 patients across nine cancer types (brain, colorectal, advanced breast, head/neck, lung, mesothelioma, melanoma, ovarian, and prostate). Anchor-based MIDs for within-group change and between-group differences in change over time were obtained via mean change method and linear regression, respectively. Separate MIDs were estimated for improvements and deteriorations. Distribution-based estimates were derived and compared with anchor-based MIDs.ResultsAnchor-based MIDs mostly ranged from 5 to 10 points. Differences in MIDs for improvement vs deterioration, for both within-group and between-group, were mostly within a 2-points range. Larger differences between within-group and between-group MIDs were observed for several scales in ovarian, lung and head/neck cancer. Most anchor-based MIDs ranged between 0.3 SD and 0.5 SD distribution-based estimates.ConclusionsOur results reinforce recent claims that no single MID can be applied to all EORTC QLQ-C30 scales and disease settings. MIDs varied by scale, improvement/deterioration, within/between comparisons and by cancer type. Researchers applying commonly used rules of thumb must be aware of the risk of dismissing changes that are clinically meaningful or underpowering analyses when smaller MIDs apply. Show less
Petersen, M.A.; Aaronson, N.K.; Arraras, J.I.; Chie, W.C.; Conroy, T.; Costantini, A.; ... ; European Org Res Treatment Cancer 2018
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... Show moreAim: 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. (C) 2010 Elsevier Ltd. All rights reserved. Show less
