Chinese herbal medicine for COVID-19: Current evidence with systematic review and meta-analysis

BACKGROUND: There is currently no drug or therapy that cures COVID-19, a highly contagious and life-threatening disease. OBJECTIVE: This systematic review and meta-analysis summarized contemporary studies that report the use of Chinese herbal medicine (CHM) to treat COVID-19. SEARCH STRATEGY: Six electronic databases (PubMed/MEDLINE, Cochrane Library, ScienceDirect, Google Scholar, Wanfang Data and China National Knowledge Infrastructure) were searched from their beginning to May 15, 2020 with the following search terms: traditional Chinese medicine, Chinese medicine, Chinese herbal medicine, COVID-19, new coronavirus pneumonia, SARS-CoV-2, and randomized controlled trial. INCLUSION CRITERIA: Randomized controlled trials (RCTs) from peer-reviewed journals and non-reviewed publications were included. Further, included RCTs had a control group that was given standard care (SC; such as conventional Western medicine treatments or routine medical care), and a treatment group that was given SC plus CHM. DATA EXTRACTION AND ANALYSIS: Two evaluators screened and collected literature independently; information on participants, study design, interventions, follow-up and adverse events were extracted, and risk of bias was assessed. The primary outcomes included scores that represented changes in symptoms and signs over the course of treatment. Secondary outcomes included the level of inflammatory markers, improvement of pneumonia confirmed by computed tomography (CT), and adverse events. Dichotomous data were expressed as risk ratio or hazard ratio with 95% confidence interval (CI); where time-to-event analysis was used, outcomes were expressed as odds ratio with 95% CI. Continuous data were expressed as difference in means (MD) with 95% CI, and standardized mean difference (SMD) was used when different outcome scales were pooled. RESULTS: Seven original studies, comprising a total of 732 adults, were included in this meta-analysis. Compared to SC alone, CHM plus SC had a superior effect on the change of symptom and sign score (−1.30 by SMD, 95% CI [−2.43, −0.16]; 3 studies; n = 261, P = 0.03), on inflammatory marker C-reactive protein (CRP, mg/L; −11.82 by MD, 95% CI [−17.95, −5.69]; 5 studies; n = 325, P = 0.0002), on number of patients with improved lung CT scans (1.34 by risk ratio, 95% CI [1.19, 1.51]; 4 studies; n = 489, P < 0.00001). No significant adverse events were recorded in the included RCTs. CONCLUSION: Current evidence shows that CHM, as an adjunct treatment with standard care, helps to improve treatment outcomes in COVID-19 cases.