A review of the methods used for subjective evaluation of De Qi

De Qi refers to a series of sensations experienced when acupuncture is performed at acupoints. De Qi comprises needling sensations felt by the patient, and the sensations perceived by the acupuncturist. Classical Traditional Chinese Medicine theory states that De Qi is closely related to curative effect. In modern studies, the main index that researchers have used to evaluate De Qi was the needling sensation reported by the patient. Between 1st Aug and 31st Oct 2014, we conducted an electronic database search of all fields in Chinese and English to select literature assessing acupuncture needle sensations. We then reviewed the methods used within these studies to evaluate De Qi. The methods included simple evaluation, and the use of a De Qi scale/questionnaire. The simple evaluation, a qualitative evaluation, was judged by typical sensations felt by the patient after needling at acupoints, such as soreness, numbness, fullness, and heaviness. This method was easy and practicable, and had been adopted widely by Chinese researchers. In contrast, the De Qi scale/questionnaire, a quantitative evaluation, had multiple compiling methods available for evaluating the intensity of De Qi. The standardization and objectification of the De Qi scale/questionnaire effectively improved the quality of studies on De Qi, thereby these scales/questionnaires have been acknowledged and applied by most researchers. The present review analyzed and compared the scales/questionnaires used to evaluate De Qi; furthermore, we provided suggestions for the development and improvement of these questionnaires through integration with classical De Qi theory.