[Development of a quality of life rating scale for patients with chronic neurological diseases]

A significant concern among health care personnel is the assessment of the quality of life (QOL) among patients with chronic neurological diseases such as amyotrophic lateral sclerosis, spinocerebellar degeneration and Parkinson disease, which are designated as intractable diseases by the Ministry of Health and Welfare of Japan. A purposes for the assessment of QOL of patients with intractable diseases is to allow evaluation of whether the increased QOL resulted from remission of clinical symptoms, social support, or improvement in ADL and environment. QOL for these patients was defined an attainment of a desirable life, which is reflected in acceptance of their own disease, satisfaction in their life, and morale. An item-pool consisting of 87 questions was derived from our observation of the patients, reviews of previous literature and suggestions from specialists in the field. Based on a preliminary test administered to 88 patients living in communities, 27 items were selected for the final QOL scale through factor analysis. Correlation coefficients between QOL score and each item were in the range of 0.192 to 0.655 and Cronbach's alpha-coefficient was 0.871, showing a moderate and high internal consistency, respectively. In an extended survey administered to 259 patients including those for the preliminary test, high test-retest reliability was demonstrated (r = 0.854). The factor structure of the questionnaire assessed by a factor analysis with Varimax rotation was consistent with our original concept of QOL, suggesting a high validity of the QOL scale.