Psychometrics and population norm of the Chinese (HK) SF-36 Health Survey⋮rsion 2

Objective: To establish the psychometric properties and norm of the Chinese (HK) SF-36 version 2 Health Survey for the adult population in Hong Kong (HK) to facilitate its application and interpretation. Design: A cross-sectional random telephone survey of the general adult population. Subjects: 2410 Chinese adults randomly selected from the general Chinese adult population in Hong Kong. The mean age of the subjects was 42.9 (S.D. 17.3) years, 48% were men and 38% had one or more chronic disease. Main outcome measures: Responses to the SF-36v2 Health Survey questions were extracted. Item-scale correlations, internal and test-retest reliabilities, and the factor structure of the SF-36v2 Health Survey scores were analysed. The SF-36v2 Health Survey scores were calculated by the standard algorithm to establish the population norm. Results: All items had 100% scaling success indicating discriminant validity. Internal consistency and test-retest reliabilities of all scales were good (coefficients 0.66 to 0.89). The hypothesized two-factor structure underlying construction of the physical and mental health summary scales was confirmed. The psychometric properties of the SF-36v2 Health Survey were generally better than version 1. There were significant differences in the population norms between versions 1 and 2 of the Chinese (HK) SF-36 Health Survey, especially in the role-physical and role-emotional scales. Conclusion: The Chinese (HK) SF-36v2 Health Survey is valid and reliable for measuring HRQOL of Chinese adults in Hong Kong, and population norm is now available to support the interpretation of its scores.