BCQ+: a body constitution questionnaire to assess Yang-Xu. Part II: Evaluation of reliability and validity

Integrated medicine has become an important issue in this century. In order to bridge the gap between traditional Chinese medicine (TCM) and modern medicine, we have established a first final version of a Yang-Xu constitution questionnaire, the BCQ+, in a previous study. The objective of the present investigation is to assess the reliability and validity of the BCQ+.

A total of 1,310 eligible participants, aged between 20-60, no disease onset in the past month, who received health examination in teaching hospitals were recruited. The BCQ+ was developed and psychometrically evaluated to ascertain and validate the factor structure of the BCQ+. Furthermore, the reliability and validity of the BCQ+ were examined.

19 items from the BCQ+ were developed. Exploratory factor analysis identified 5 primary domains that represent the Yang-Xu constitution and correspond to the diminishing energy levels of 5 different body areas: head, chest, limbs, abdominal cavity, and body surface. Cronbach's alpha ranged between 0.55-0.88 and the intraclass correlation coefficients were >0.7 for most of the 19 questions. The diagnoses of Yang-Xu by the BCQ+ and an experienced TCM doctor were consistent. Systolic blood pressure (SBP) was used as an indicator of concurrent validity of the BCQ+, and it was found that higher Yang-Xu scores were associated with a lower SBP.

Five domains with 19 items in the BCQ+ were developed. The BCQ+ is a valid and potentially useful tool for evaluating the Yang-Xu constitution in clinical practice and research.