Factor analysis of traditional Chinese medicine symptoms for identification of syndrome patterns associated with idiopathic short stature in children

Abstract

Objectives: Diagnosing idiopathic short stature (ISS) in Traditional Chinese Medicine (TCM) remains challenging partly because the symptoms and syndrome patterns vary among ISS patients and studies. We aimed to use factor analysis of TCM symptoms to identify syndrome patterns associated with ISS in children on the basis of TCM theory.

Materials and methods: A cross-sectional study was conducted at Taipei Tzu Chi Hospital, New Taipei City, Taiwan, from October 1, 2014, to February 28, 2016. The study included 957 individuals who were newly diagnosed with ISS through simple random sampling. The outcome measures comprised 34 TCM symptoms related to children's growth, and these symptoms were assessed using a five-level self-report questionnaire, which was completed by children and their parents. A factor analysis was conducted for the extraction of underlying factors.

Results: A total of 26 symptoms had factor loadings higher than the exact threshold value (0.4), and five factors were extracted. Factor 1, comprising seven symptoms, was interpreted as "yin deficiency and fire hyperactivity of kidney syndrome." Factor 2, which included eight symptoms, was interpreted as "phlegm dampness stagnation of spleen syndrome." Factor 4, which included five symptoms, was interpreted as "liver qi invading the spleen syndrome." Factor 5, which included four symptoms, was interpreted as "spleen-stomach weakness syndrome." Factor 3, which included four symptoms, was uninterpretable. Factors 1-5 accounted for 10%, 9%, 8%, 7%, and 6% of the total variance.

Conclusion: Four major TCM syndrome patterns, namely, "yin deficiency and fire hyperactivity of kidney syndrome," "phlegm dampness stagnation of spleen syndrome," "Liver qi invading the spleen syndrome," and "spleen-stomach weakness syndrome" were identified and accounted for 40% of the total variance of the 34 TCM symptoms surveyed in children with ISS. Our findings may facilitate the diagnosis of ISS and the optimization of treatment strategies.

Keywords: Children; Idiopathic short stature; Symptoms; Syndrome patterns; Traditional Chinese Medicine.

Figure 1

The distribution in the height-for-age chart of the boys (a) and girls (b) in this study

Figure 2

Combined use of the scree plot of eigenvalues and parallel analysis for choosing the appropriate number of factors. For the scree plot, the number of factors was chosen at the point where the eigenvalue was > 1. For parallel analysis, factors were recomputed, and the new eigenvalues were plotted on the same graph as the scree plot. The elbow of the scree plots and the crossing points between the line from the parallel analysis are six extracted factors