RESUMEN
Chinese Medicine Questionnaire (CCMQ-J) consists of sixty independent questionnaires and 9 physical constitutions called subscales. One type is balanced constitution (i.e., gentleness), and the following eight types represent unbalanced constitution: Qi-deficiency constitution, Yang-deficiency constitution, Yin-deficiency constitution, Phlegm-dampness constitution, Damp-heat constitution, Stagnant Blood constitution, Stagnant Qi constitution, and Inherited Special constitution. In this study, we proposed to determine optimal number of groups in 851 participants recruited from crowdsourcing answered CCMQ-J questionnaire consisting of 60 questions. In the present study, we applied k-means clustering with gap statistics to the questionnaire data and the number of optimal groups was estimated by five. The five groups are mainly characterized by 3 subscales in CCMQ-J, i.e. (i) two subscales corresponding to Yang-deficiency and Qi-depress, (ii) three subscales corresponding to gentleness, Yang-deficiency and Qi-depress (iii) Yang-deficiency, (iv) gentleness, and (v) Qi-depress. In the crowdsourcing survey, two subscales, Yang-deficient and Qi-depress are the most frequently occurred in current Japanese people.