Table 1 Fundamental principles and methods of CM theory: pattern identification [30, 31]

The Chinese medicine (CM) theoretical system evolved over centuries. Its fundamental principle is that the determination of CM interventions must be based on pattern differentiation (also called syndrome differentiation, or “Bian-Zheng-Lun-Zhi” in Chinese), a primary CM method of understanding and treating diseases. According to CM theory, a pattern (also termed a syndrome or “Zheng” in Chinese) is a pathological cluster or summary of signs and symptoms at a particular stage of a disease. The pattern may include the cause(s), pathological features, properties, and the relationship between any pathogens involved and the body’s resistance. The patterns are named according to a cluster of associated signs and symptoms described in terms of yin, yang, exterior, interior, cold, heat, deficiency, and excess. In general, a pattern is composed of “location of disease” and “feature of disease.”

A “pattern” (Zheng) is obtained through analyzing the “symptoms,” while the “disease,” especially in Western terms, comprises the whole morbid process and may include several different patterns. Specifically, pattern differentiation refers to the analysis and summarization of the clinical symptoms obtained through the four diagnostic methods of CM (inspection, auscultation and smell, inquiry, and pulse taking and palpation), after which CM practitioners can accordingly determine the specific treatment. In practice, one disease may include several different CM patterns, and conversely, different diseases may exhibit the same CM pattern in the course of their development. Thus, the application of pattern differentiation may “treat the same diseases with different methods,” or it may “treat different diseases with the same therapeutic method.”

Accurate CM pattern differentiation is critical. It provides a diagnostic label, it guides the choice of CM interventions, such as moxibustion, and it gives access to the historical record of the treatments other doctors over centuries have used. In clinical practice, pattern diagnosis can help the practitioner determine a treatment principle and methods of moxibustion therapy, including the selection of acupoints, types, materials, and techniques. For example, the treatment principles of moxibustion used for excessive syndrome and deficiency syndrome are very different. For SRs of moxibustion, if the primary studies included pattern differentiation, the concept of the studied pattern should be carried out throughout the entire process with regard to the rationale of the review design, inclusion and exclusion criteria, selection of moxibustion intervention(s), outcomes, data interpretation and additional analyses, etc.