Development and evaluation of short form of constitution in Chinese medicine questionnaire: a national epidemiological survey data of 21 948 case.

ABSTRACT

OBJECTIVE: To develop the best short form of constitution in Chinese medicine questionnaire (CCMQ) and evaluate its psychometric properties in Chinese population. METHODS: A total of 21 948 subjects were used to refine the short form. Correlation coefficient, exploratory factor analysis (EFA) and Cronbach's alpha coefficient were used to analyze and select items to form the short form. Separate sample of 205 subjects were collected to further evaluate the short from. EFA, confirmatory factor analysis (CFA), item-scale correlation, discriminant validity, internal consistency reliability and split-half reliability were carried out to evaluate the short form. RESULTS: The short form CCMQ included 26 items. Seven common factors of characteristic root > 1 were extracted to explain 58.488% of the total variation. Result of CFA was consistent with the 9-factors structure. The mean differences of Blood-stasis body constitution and Qi-stagnation body constitution had statistical significance in body mass index differentiation. Cronbach's alpha coefficient of short form CCMQ was 0.863. The split-half reliability of total scale was 0.813, and each scale was 0.568-0.770. The item-scale correlations ranged from 0.620-0.849. CONCLUSION: The short form CCMQ consisted of 26 items with good psychometric properties. The short form should be recommended for the measurement of health of Chinese population in any clinical trial.