A critical review to grading systems and recommendations of traditional Chinese medicine guidelines

Objectives To investigate how many traditional Chinese medicine (TCM) guidelines adopted a grading system and the differences among them, and the distribution of level of evidence used to support TCM recommendations. Methods A comprehensive search of relevant guideline webpages and literature databases were undertaken from inception to August 2018 to identify guidelines including TCM interventions. Two independent reviewers extracted the information about grading systems and recommendations. Results One hundred forty-two TCM guidelines were included, among which, 68 (47.9%) adopted a total of eight grading systems. The definitions, letters, and codes among these systems varied significantly. A total of 1284 recommendations were extracted from included TCM guidelines. More than 60% recommendations were based on a low and very low level of evidence (level C:33.4% and level D: 30.2%). Only 7.8% recommendations were rated as strong recommendation (grade I), while 76.2% recommendations were rated as conditional recommendation (grade II). Conclusions Various grading systems were used in TCM guidelines, which might confuse guideline users. The low proportion of high level of evidence in TCM recommendations might downgrade the confidence to TCM interventions.