Development of a quality of life questionnaire for Korean asthmatics

Oh, Sang Woo; Cho, You Sook; Lim, Mi Kyoung; Yoo, Bin; Moon, Hee Bom

Abstract

BACKGROUND AND OBJECTIVE: The outcome of asthma treatment has traditionally been assessed by measuring the conventional clinical parameters such as symptoms, expiratory flow rates and needs for medications. But none of them tells us whether the patients are actually able to function properly in their lives. Only assessment of the quality of life (QOL) can reflect the parts of patients lives affected by the disease. However, there is no measure to assess the quality of life of patients with any chronic diseases in Korea yet. We developed the QOL Questionnaire for Korean Asthmatics and evaluated its measurement properties. METHOD: The questionnaire was composed of 18 items in four domains : i.e. activity limitation (6 items), symptoms (5 items), emotional function (3 items) and environmental stimuli (4 items). At our out-patient clinic, 32 adults with moderate to severe persistent bronchial asthma were enrolled. The study design consisted of 4 week unblinded single cohort with visits at 0 and 4 weeks, and the patients were asked to answer the questionnaire by self administration method at the two separate visits. Forced expiratory volume for 1 second (FEV1) and peak expiratory flow rate (PEFR) were recorded at each visit. According to the patients and physicians global assessment, the patients were divided into two groups, i.e. stable and changed (improved). The responsiveness, reproducibility and validity of the questionnaire were evaluated.
RESULTS
The total QOL scores at the second visit in the changed group were significantly higher than those at the first visit. The score differences between the two visits in the changed group were higher than in the stable group. In the stable group, the responses to the questionnaire were reproducible. The QOL scores showed good longitudinal correlation with the expiratory flow rates, whereas FEV1 did not correlate with the QOL in cross-sectional analysis.
CONCLUSION
The questionnaire proved to be reproducible, responsive and valid in the subjects. It could be recommended for the outcome evaluation of Korean asthmatics.