Development of the core outcome set of traditional Chinese medicine syndromes for bradyarrhythmia based on mixed methods

Objective: Develop a core outcome set (COS) of traditional Chinese medicine (TCM) syndromes for bradyarrhythmia to provide a standardized reference for the efficacy evaluation of TCM syndromes in clinical research. Methods: A systematic review and a retrospective study were used to construct the original long list of TCM syndromes for bradyarrhythmia. The original list was refined through steering committee meeting and semi - structured interviews. Questionnaires were developed based on the original list, and two rounds of Delphi surveys were conducted among TCM clinicians and researchers. A COS of TCM syndromes for bradyarrhythmia was developed after a consensus meeting. Results: After data extraction and discussion, the COS of TCM syndromes for bradyarrhythmia was constructed in the form of syndrome elements. 13 syndrome elements and their manifestations were included in the round 1 of the Delphi survey. Fifty - four participants completed the round 1 of the Delphi survey, fifty participants completed the round 2 of the Delphi survey, and twelve participants attended the online consensus meeting. Finally, the COS of TCM syndromes for bradyarrhythmia included seven syndrome elements and their manifestations, including syndrome of heart yang deficiency, syndrome of heart qi deficiency, syndrome of heart blood deficiency, syndrome of heart blood stasis obstruction, syndrome of kidney yang deficiency, syndrome of spleen yang deficiency, and phlegm syndrome. Conclusion: The COS of TCM syndromes for bradyarrhythmia can help researchers select the outcomes reported in clinical trials and improve the consistency of the efficacy evaluation of TCM syndromes in clinical trials.