Reliability and Validity of the King's Health Questionnaire for Male Lower Urinary Tract Symptoms in Taiwan

Objectives: To investigate the reliability and validity of the King's Health Questionnaire (KHQ), and understand the impacts of lower urinary tract symptom (LUTS) on health-related quality of life (HR-QoL). Methods: A cross-sectional design was used and a convenience of 393 men participated in the study. The reliability was measured by testing the Cronbach's coefficients. Factor analysis was used to explore the underlying factor structure of the KHQ. The discriminant validity was assessed using the one-way analysis of variance (ANOVA) tests with post hoc analysis (Games-Howell method) by comparing the differences scores in KHQ domains between men with three LUTS severity groups (mild, moderate, and severe). Results: Men with severe, moderate, mild LUTS accounted for 7.9, 25.4, and 66.7%, respectively. Internal consistency of KHQ was excellent with Cronbach's coefficients of 0.750-0.943. Factor analysis showed three underlying components to explain constructive validity. The KHQ subscores in both the severe and moderate LUTS groups were significantly higher than those in mild LUTS group (all P < 0.05), implying that the discriminant validity was adequate. Excepting for two single-item questions, the first three greater disparities in KHQ domains between the severe and mild LUTS groups were Emotion, Sleeping/Energy, and Physical limitation, while the least disparities was found in Personal relationships domain. Conclusion: LUTS could produce a substantial impact on different domains of HR-QoL. The traditional Chinese KHQ has suitable reliability and validity for men with general LUTS, and might be a useful tool for HR-QoL measure in future.