Abstract

If we want to assess the quality of life(QoL) in patients with schizophrenic disorder, a scale which includes various constructs of QoL and reflects subjective appraisals of the patients is needed. For those purposes, this study was designed to develop a QoL scale which includes various domains of the QoL in a sample of patients with schizophrenic disorder. The subjects were composed of 363 patients with schizophrenic disorder. A preliminary study using 43 items developed from the existing QoL scales by considering the content and the property of them was performed from the existing QoL scales by considering the content and the property of them was performed with university students. Thirty-six items selected from the preliminary study were administered to the subjects. After carrying out Explanatory Factor Analysis by using x^2-test, the best model for factor structure of the scale was selected by referring the RMSEA(Root Mean Square Error of Approximation) and ECVI(Expected Cross-Validation Index). The Rasch model, one of the item response theories was used to verify the reliability of the items and the subjects, and the fitness of the items, the subjects, and the number of categories. The results of analyses revealed that a model with five factors was best fitted. The factors were labeled as `economic domain`, `general domain`, `physical domain`, `occupational/social domain`, and `affective domain`. By the item analyses performed two times, the reliability of the items and the subjects was improved, and the fitness of the items, the subjects, and the number of categories (0, 1, 2, 3, 4) showed to be appropriate. Finally, the Happy-QoL Scale composed of five factors having five items in each (total 25 items) was developed. The risk factors predicting low reliability to the response of the QoL scale were the education level and the treatment type of the subjects, and the concurrent validity of the Happy-QoL scale with GHQ/QL-12(General Health Questionnaire/Quality of Life-12) was good. The limitations of this study and the issues for future study were briefly described.