The Development of Korean Health Related Quality of Life Scale (KQUOLS): Testing Reliability and Validity

ABSTRACT

BACKGROUND: Korean health related Quality of Life Scale(KQOLS) was developed to measure the quality of life reflecting Korean's own language expression and culture. In order to confide in the results of KQOLS, it is necessary to establish verification of the psychometric properties(reliability, validity, responsiveness). METHODS: KQOLS's final 46 items and item option responses were established by expert panels. Reliability was tested by 2 weeks test-retest method and internal consistency method. Validity was tested by factor analysis and clinical validity. Sensitivity and specificity for detecting treatment-related changes were also tested. RESULTS: A high degree of internal consistency was observed for each of domains(Cronbach's alpha value of 0.77 or higher). Two weeks test-retest reliability correlation coefficients scores were highly significant except health perception domain. A principal components analysis identified 9 factors with eight values greater than 1.0 which were approximately the same as intended domains. Normal control group had statistically significant higher scores than patients group except in spiritual health and social function domains. Improved group of patients had statistically significant higher scores than non-improved group of patients after treatment except in spiritual health and health status perception domains. CONCLUSION: Korean health related Quality of Life Scale(KQOLS) is both a valid and a reliable instrument, but fine refinements such as items revision and item response options modification will be needed.