Outcome measures in clinical trials of traditional Chinese medicine for stable angina pectoris

Objective: This work aimed to present a descriptive analysis of the outcome measures used in clinical trials of traditional Chinese medicine (TCM) for patients with stable angina pectoris, and to provide baseline data for the development of core outcome sets (COSs) for relevant clinical trials. Methods: Medical databases were searched to identify randomized trials of the effects of TCM for the treatment of stable angina pectoris. Outcome measures of each trial were extracted. Descriptive statistics were used to analyze the baseline characteristics of outcomes in clinical trials of TCM. Results: 94 randomized trials (with 9,111 participants) involving 79 different outcomes were identified. The mean number of outcomes was 5 (1-21 per trial). The 5 most commonly reported outcomes were efficacy rate of electrocardiogram, efficacy rate of angina pectoris, efficacy rate of TCM syndrome, fasting lipid indices, and withdrawal rate of nitroglycerin. Several challenges were identified: (1) significant heterogeneity of outcomes and differences in the technique and timing of the measurement of the same outcome; (2) transformation of continuous data into categorical data and presented as such in >90％ of trials; (3) few trials on the outcomes associated with the advantages and characteristics of TCM; and (4) selective reporting of outcomes. Conclusions: The outcomes used are excessively heterogenous, and the choice of some outcomes (timing and techniques) for measurement is confusing or inappropriate. Hence, developing and implementing a COS is necessary for greater consistency.