Outcome indicators in clinical trials on traditional Chinese medicine treatment of microvascular angina

Abstract

This study reviewed the current status of the use of outcome indicators in randomized controlled trial(RCT) on traditional Chinese medicine(TCM) treatment of microvascular angina(MVA) and analyzed the existing problems and possible solutions, aiming to provide a basis for the design of high-quality RCT and the establishment of core outcome sets for MVA. CNKI, Wanfang, VIP, SinoMed, PubMed, EMbase, Cochrane Library, Web of Science, and 2 clinical trial registries were searched for the RCT on TCM treatment of MVA according to pre-defined criteria. The Cochrane's risk of bias assessment tool was used to evaluate the methodological quality of the included RCT and the use of outcome indicators was summarized. A total of 69 RCTs were included, from which 100 outcome indicators were extracted, with the frequency of 430. The extracted outcome indicators belonged to 8 domains: response rate, symptoms and signs, physical and chemical examinations, TCM efficacy, safety, quality of life, economic evaluation, and long-term prognosis. The indicators of physical and chemical examinations were the most(70 indicators with the frequency of 211), followed by those of response rate(7 indicators with the frequency of 73) and symptoms and signs(7 indicators with the frequency of 54). The outcome indicators with higher frequency were adverse reactions, angina attack frequency, clinical efficacy, endothelin-1, total duration of treadmill exercise, and hypersensitive C-reactive protein. The RCT on TCM treatment of MVA had the following problems: irregular reporting of adverse reactions, diverse indicators with low frequency, lack of attention to the application of endpoint indicators, insufficient use of TCM differentiation and efficacy indicators, non-standard evaluation criteria and failure to reflect the basic characteristics of TCM. A unified MVA syndrome differentiation standard should be established, on the basis of which an MVA treatment efficacy evaluation system and core outcome indicator set that highlights the characteristics of TCM with patient-reported outcomes as the starting point should be established to improve the clinical research and research value.