A traditional Chinese patent medicine—Suhuang zhike capsule for cough variant asthma in adults: A protocol of systematic review and meta-analysis of randomized controlled trials

BACKGROUND: Many people with cough variant asthma use Traditional Chinese Patent Medicine-Suhuang anti-tussive capsule to help reduce symptoms. However there is no systematic reviews had promising its efficacy and safety for cough variant asthma. METHODS: Four English databases (PubMed, Web of science, EMBASE, and Springer Cochrane Library) and 4 Chinese databases (Wanfang Database, Chinese Scientific Journal Database, China National Knowledge Infrastructure Database, and Chinese Biomedical Literature Database) were researched for the randomized controlled trials of Suhuang anti-tussive capsule for cough variant asthma. The search was limited to human studies, using the search keywords or free-text terms “cough,” “cough variant asthma,” “Suhuang Zhike capsul,”“Suhuang anti-tussive capsul,” and “randomized clinical trials.” Two reviewers individually extracted data from the included randomized controlled trials (RCTs). Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. The primary outcomes include the frequency of asthma exacerbations during follow-up, asthmatic symptoms by validated instruments (including symptom scores, Likert scale, visual analogue scale). Lung function, serum immunoglobulin E, blood eosinophil count, phlegm eosinophil count, tumor necrosis factor-a, interleukin-1b, and adverse effects (numbers of participants experiencing each adverse events) will be assessed as the secondary outcome. Meta-analysis will be performed using RevMan5.3.5 software provided by the Cochrane Collaboration. RESULTS: This study will provide high-quality synthesis based on current evidence of Suhuang anti-tussive capsule treatment for cough variant asthma. CONCLUSION: This analysis will provide updated evidence for whether Suhuang anti-tussive capsule is an effective and safe intervention for cough variant asthma. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019139695.