Objectives: Yin Deficiency (YD) is a pathophysiologic pattern that manifests with emaciation, dry mouth, tidal fever, Five Center Heat, night sweats, and malar flushing. The purpose of the present study was to develop and validate a new YD metric, the Yin Deficiency Scale (YDS), to define an optimum cutoff point for the YDS, and to examine the relationships between YD and Cold-Heat patterns.
Methods: A total of 169 outpatients and 83 college students were asked to complete the YDS. The college students were also asked to complete the Yin Deficiency Questionnaire (YDQ) and Cold-Heat Questionnaire (CHQ). Twelve clinicians determined whether or not the 169 outpatients had YD. YDS and YDQ data were used to estimate the internal consistency, construct validity, and concurrent validity of the YDS. CHQ data were used to examine the relationships between YDS and CHQ subscale scores. Total YDS scores and the clinicians' diagnoses of the outpatients were used to define an optimum cutoff score for the YDS.
Results: The 27-item YDS had satisfactory internal consistency (α=0.885) and concurrent validity, with correlations between the YDS and YDQ subscale scores. A total of eight factors were extracted in the test of construct validity, using principal component analysis, and the overall variance explained by all factors was 63.1%. Among the eight factors, cough, fever, and skin-related factors were associated only with Heat pattern, whereas pain, urine, and fatigue-related factors were associated with both Cold and Heat patterns. In the receiver operating characteristic curve analysis, the sensitivity, specificity, and area under the curve of the YDS were 73.7%, 84.8%, and 0.875, respectively. The optimum cutoff score was defined as 10 points.
Conclusions: The results of this study suggest that the YDS is a reliable and valid instrument for evaluating YD.