RESUMEN
<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>