Background  The Chinese medical archive, Shang-Han Lun, is said to be written by ZHANG Zhong-jing (150–219 A.D.). This great influential work introduced the specific symptoms of six-channel disorders (Tai-Yang, Yang-Ming, Shao-Yang, Tai-Yin, Shao-Yin, and Jue-Yin) and their corresponding treatments, the combined syndromes, deterioration due to malpractice, and the concept of six-channel transitions. The concept of Shang-Han Lun is widely accepted by Chinese herbal doctors. However, no clinical data about Shang-Han symptoms are described in oriental or western medical reports.
Methods  The clinical prescription data of traditional Chinese medicine visits were extracted under the National Health Insurance in Taiwan. The application rate of 42 Shang-Han formulae in clinical practice was analyzed in detail with the software SPSS.
Results  Between 1999 and 2002, the prescription rate of Shang-Han formula was only 5.22% among a total of 528 889 576 Chinese herbal formula prescriptions. The most frequently used formula was Tai-Yang formulae (71.31%), followed by Shao-Yang formulae (17.49%) and the most commonly prescribed individual Shang-Han formulae were Ge-Gen Tang (16.11%), Shao-Yao-Gan-Cao Tang (12.97%), Xiao-Qing-Long Tang (11.79%), Ban-Xia Xie-Xin Tang (10.24%), and Xiao-Chai-Hu Tang (9.11%), which comprised 60.22% of the utilization rate of total Shang-Han formulae.
Conclusions  From the prescription patterns of Shang-Han formulae, there was no evidence of transitions among the six channels. Despite the fundamental role of Shang-Han Lun in traditional Chinese medicine, prescription of Shang-Han formulae was limited in clinical practice.