Preparation of a quality of life (QOL) questionnaire for patients with type II diabetes and prospects for its clinical application.

Modification of the lifestyle centering on dietary therapy has been proven to be effective for the treatment of diabetes mellitus, which is increasing progressively. However, lifetime treatment for diabetes inevitably puts economic as well as physical and mental burdens on the patients, and many patients drop out by discontinuing or neglecting treatment, promoting exacerbation of the condition. In this study, an original "Quality of life (QOL) questionnaire for patients with type II diabetes" using a visual analogue scale was tentatively prepared. To evaluate the reliability and validity of this questionnaire, 126 patients (64 males and 62 females) being treated as outpatients or inpatients at 8 university or public hospitals in Fukuoka Prefecture were selected at random, and valid answers from 73 patients were analyzed. From the 46 questions, those in which no significant correlation was observed or which were not answered by many patients were excluded. Since the value of sampling adequacy was 0.673 according to the Kaiser-Meyer-Olkin (KMO) measure, the sampling adequacy is considered to have been average. When factor analysis by varimax rotation was performed using the Statistical Package for Social Science, 4 factors consisting of 18 question items were extracted. Eventually, these 4 factors of 18 questions were adopted for the QOL questionnaire for patients with type II diabetes. The alpha values of the 4 factors were high at 0.867, 0.795, 0.706, and 0.756. These results confirmed the internal consistency of the questionnaire and sufficient reliability of this analytical method.