International development of an EORTC questionnaire for assessing health-related quality of life in chronic myeloid leukemia patients: the EORTC QLQ-CML24

Background: Health-related quality of life (HRQOL) is a key aspect for chronic myeloid leukemia (CML) patients. The aim of this study was to develop a disease-specific HRQOL questionnaire for patients with CML to supplement the European Organization for Research and Treatment of Cancer (EORTC)-QLQ C30. Patients and methods: The process followed a predefined and systematic stepwise iterative process as defined by the EORTC guidelines for questionnaire development. The process was divided into 3 phases: (1) generation of relevant HRQOL issues, (2) operationalization of the HRQOL issues into a set of items, and (3) pretesting the questionnaire for relevance and acceptability. Descriptive statistics and psychometric analyses were also performed. Results: Overall, 655 CML patients were enrolled in 10 countries including the USA and countries in Europe and Asia. Interviews with health-care professionals experienced in CML (n = 59) were also conducted. Results from the interviews, clinical experiences, and statistical analyses were used to develop the EORTC QLQ-CML24. The final module consists of 24 items assessing the following aspects: symptom burden, impact on daily life and on worry/mood, body image problems, and satisfaction with care and with social life. Internal consistency, assessed with Cronbach's alpha coefficients, ranged from 0.73 to 0.83 for the proposed scales. Conclusion: The EORTC QLQ-CML24 is an internationally developed HRQOL questionnaire for CML patients, and its implementation in clinical research and practice can provide important information to facilitate clinical decision-making.