| Background The Constitution in Chinese Medicine Questionnaire (CCMQ) was developed in Mainland China to classify people into nine physiological body constitution (BC) types based on traditional Chinese medicine (TCM) theories. The validity and reliability are not clear especially in Chinese populations outside Mainland China. Objectives The aim of this study was to adapt and validate the CCMQ in Hong Kong Chinese. We wanted to establish evidence on its content and construct validity, reliability, and responsiveness. Methods The CCMQ was reviewed and adapted to be linguistically appropriated for Chinese in Hong Kong by a professional translator, and then evaluated by cognitive debriefing with 10 patients and 10 Chinese Medicine Practitioners (CMP) to assess the clarity and validity of the content. Data of the cognitive debriefing were reviewed qualitatively to identify items that needed revision, and quantitatively to determine the content validity index (CVI) of each item. A cross-sectional study on 1084 Chinese adult patients recruited from TCM and Western Medicine (WM) primary care general outpatient clinics was carried out to test construct validity, reliability and importance of the CCMQ. Each subject completed the CCMQ, SF-12v2 and a structured questionnaire on demographics and morbidities, administered by a trained interviewer, before being assessed by a Chinese medicine Practitioner (CMP). 225 patients were retested two weeks later to assess the test-retest reliability and 402 subjects were followed up by telephone six months later to evaluate the responsiveness to change in health condition. Results The original Chinese terms of 4 items (3, 26, 31 and 32) of the CCMQ were not commonly used in Hong Kong and they were adapted to semantically equivalent Chinese phrases. Cognitive debriefing confirmed content validity and the clarity (CVI of 50% to 100%) of the HK versions of CCMQ. 2128 patients were invited and 1084 (51%) subjects completed the cross-sectional study. 98.6% subjects could be classified into one or more BC types by the CCMQ. 20% of subjects belonged to Gentleness (balanced) BC type. Scaling success rates were 85.7% to 100% for the 9 BC scales of CCMQ. Construct validity was supported by a significant moderate correlations between CCMQ and the SF-12v2 scores and the confirmatory factor analysis shown a reproducible structure to the hypothesized original version. People classified to have the Gentleness BC type by CCMQ had better health-related quality of life (higher SF-12 scores) than those with the other (imbalanced) BC types. Internal consistency (reliability) (Cronbach’s alpha >0.6) and test-retest reliability were also satisfactory (ICC>0.6) for all scales. However, the sensitivity and specificity of the CCMQ in predicting the BC type diagnosed by CMP was only 3 fair, ranging from 42.7% to 82.7 % for the different BC types. 27.6% subjects had a change from the imbalanced BC types to Gentleness BC type after 6 months. Conclusions The CCMQ was adapted for HK Chinese, and was proven to be a valid, reliable and responsive measure of physiological BC type. People classified to have imbalanced BC types had significantly lower health-related quality of life than those with Gentleness BC type, which supported the validity and importance of the TCM concept of physiological BC type. |