title: BCQ+: a body constitution questionnaire to assess Yang-Xu. Part II: Evaluation of reliability and validity.
abstract: BACKGROUND
  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+.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Graduate Institute of Chinese Medical Science, China Medical University, No. 91 Hsueh-Shih Road, Taichung, Taiwan.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Chen
authors.forename: Jui-Shan
authors.initials: JS
authors.lastname: Lin
authors.forename: Jun-Dai
authors.initials: JD
authors.lastname: Lin
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Chang
authors.forename: Hsien-Wen
authors.initials: HW
authors.lastname: Kuo
authors.forename: Wen-Miin
authors.initials: WM
authors.lastname: Liang
authors.forename: Yi-Chang
authors.initials: YC
authors.lastname: Su
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D001824:Body Constitution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D016711:Yang Deficiency; D055815:Young Adult