Effectiveness and safety of Xuefu Zhuyu oral liquid on -stagnation and blood-stasis pattern in patients with stable angina, tension-type headache and primary dysmenorrhea: rationale and design of a master protocol.

We present the rationale and design of a master protocol study that clarifies the effectiveness and safety of Chinese herbal formulas on -stagnation and blood-stasis pattern (QBP). Three randomized controlled trials (RCTs) and real-world observational studies. Based on three registry cohorts of stable angina, tension-type headache and primary dysmenorrhea, patients with QBP will be enrolled in RCTs to receive either Xuefu Zhuyu (, XFZY) oral liquid or a placebo, while patients with non-QBP will be enrolled in the observational studies and experience follow-up. 1414 patients (RCTs: 574; observational studies: 840) will be recruited at seven centers in China over a 3-year period. The primary outcome is the visual analog scale of pain intensity. Adverse events will also be reported. The analysis will be undertaken separately in each sub-study, and then an overall analysis combining multiple subgroups will be performed to comprehensively investigate the effect of XFZY oral liquid. This study will provide high-quality evidence of XFZY oral liquid for QBP patients and show a paradigm of post-marketing evaluation of the effectiveness and safety for Chinese medicine following the notion of the pattern dominating different disease research models.