In this article, the authors study the factorial structure of the Italian translation of the Outcome Questionnaire 45 (OQ-45) in a sample of college students (n = 522) and psychiatric outpatients (n = 301). The relative goodness of fit of six competing models of the OQ-45 was examined using confirmatory factor analysis (CFA). Specifically, the study examined the relative fit of the most frequently presented models in the literature and three alternative models. Results of the CFA provided support for the four factor bi-level solution, suggesting that the OQ-45 is a multidimensional instrument that contains one general factor and multiple unique subscale factors.
2008 John Wiley & Sons, Ltd.