Applicability of Hyland's Living with Asthma Questionnaire for Japanese Asthmatic Patients

Objective To assess the applicability of Hyland's Living with Asthma Questionnaire (LWAQ, 1991), one of the international health-related quality of life scales, for Japanese asthmatic patients with reference to its reproducibility and validity. Subjects and Methods The LWAQ was given to randomly selected asthmatic patients on two occasions separated by a 12-week interval. Results The mean scale score in the first study (n=304) was 1.83 (range, 1.14-2.77) and logarithmic values of the scores approached normal distribution. The scale scores in the first and second (n=158) studies were well correlated (r=0.81), however, the mean score decreased (0.08) significantly. The questions were further separated into 11 domains. The sex-domain was notable for a low response rate (68%), and scale scores in the sleep-, colds- and sex-domains in the first study varied considerably from those of the other domains. Frequency distributions of scores in the five constructs (Hyland 1996) were not normal and, with the exception of the colds construct, the relations among the remaining four constructs were similar to those previously reported (Hyland 1996). Conclusion Analysis using the mean scale score, domain and construct in the LWAQ is applicable to Japanese asthmatic patients. (Internal Medicine 39: 798-803, 2000)