Reliability and validity of 12-item Short-Form health survey (SF-12) for the health status of Chinese community elderly population in Xujiahui district of Shanghai.

BACKGROUND: The 12-item Short-Form Health Survey (SF-12) is the abridged practical version of SF-36.

AIMS: This cross-sectional study was aimed to assess the reliability and validity of SF-12 for the health status of Chinese community elderly population.

METHODS: The Chinese community elderly people in Xujiahui district of Shanghai were investigated. The internal consistency reliability was assessed using Cronbach's alpha and split-half reliability coefficients. Construct validity was analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Spearman's correlation coefficient (ρ) was used for the evaluation of criterion, convergent, and discriminant validity with Spearman's ρ ≥ 0.4 as satisfactory. Comparisons of the SF-12 summary scores among populations that differed in demographics were performed for discriminant validity.

RESULTS: Total 1343 individuals aged ≥60 and <85 years old (response rate: 91.3 %) were analyzed. The Cronbach's α value (0.910) and the split-half reliability coefficient (0.812) reflected satisfactory internal consistency reliability of SF-12. EFA extracted a two-factor model (physical and mental health). About 60.7 % of the total variance was explained by the two factors. CFA showed that the two-factor solution provided a good fit to the data. Good convergent validity and discriminant validity of SF-12 were proved by the correction analyses (Spearman's ρ > 0.4) and the comparisons of the SF-12 summary scores among populations (P < 0.05). SF-12 summary scores were significantly correlated with the SF-36 summary scores (Spearman's ρ > 0.4, P < 0.05).

CONCLUSIONS: In conclusion, SF-12 had satisfactory reliability and validity in measuring health status of Chinese community elderly population in Xujiahui district of Shanghai.