Background: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is currently developing computerized adaptive testing measures for the Quality of Life Questionnaire Core-30 (QLQ-C30) scales. The work presented here describes the development of an EORTC item bank for emotional functioning (EF), which is one of the core domains of the QLQ-C30.
Methods: According to the EORTC guidelines on module development, the development of the EF item bank comprised four phases, of which the phases I-III are reported in the present paper. Phase I involved defining the theoretical framework for the EF item bank and a literature search. Phase II included pre-defined item selection steps and a multi-stage expert review process. In phase III, feedback from cancer patients from different countries was obtained.
Results: On the basis of literature search in phase I, a list of 1750 items was generated. These were reviewed and further developed in phase II with a focus on relevance, redundancy, clarity, and difficulty. The development and selection steps led to a preliminary list of 41 items. In phase III, patient interviews (N = 41; Austria, Denmark, Italy, and the UK) were conducted with the preliminary item list, resulting in some minor changes to item wording. The final list comprised 38 items.
Discussion: The phases I-III of the developmental process have resulted in an EF item list that was well accepted by patients in several countries. The items will be subjected to larger-scale field testing in order to establish their psychometric characteristics and their fit to an item response theory model.
Keywords: cancer; computer adaptive testing; emotional functioning; item response theory; oncology; quality of life.
© 2013 The Authors. Psycho-Oncology published by John Wiley & Sons, Ltd.