To improve measurement precision, the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is developing an item bank for computerized adaptive testing (CAT) of emotional functioning (EF). The item bank will be within the conceptual framework of the widely used EORTC Quality of Life questionnaire (QLQ-C30).On the basis of literature search and evaluations by international samples of experts and cancer patients, 38 candidate items were developed. The psychometric properties of the items were evaluated in a large international sample of cancer patients. This included evaluations of dimensionality, item response theory (IRT) model fit, differential item functioning (DIF), and of measurement precision/statistical power.Responses were obtained from 1,023 cancer patients from four countries. The evaluations showed that 24 items could be included in a unidimensional IRT model. DIF did not seem to have any significant impact on the estimation of EF. Evaluations indicated that the CAT measure may reduce sample size requirements by up to 50

作者：Morten Aa, Petersen；Eva-Maria, Gamper；Anna, Costantini；Johannes M, Giesinger；Bernhard, Holzner；Colin, Johnson；Monika, Sztankay；Teresa, Young；Mogens, Groenvold

来源：Journal of clinical epidemiology 2016 年 70卷