1 Introduction
Coronavirus disease 2019 (COVID-19) is a global pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2).[1] The patients of COVID-19 usually present with fever, cough, while about 23.7% of patients are accompanied by at least 1 coexisting disease.[2–6] The disease is highly contagious with a R0 value about 3 to 4.[7] The rapid increase in the number of patients put great pressure on the health care system. With the aggravation of the shortage of medical treatment, the mortality rate of the disease increases.[8] As of 15:00 on March 31, 2020, 793,278 people were diagnosed with the disease and at least 38,545 died.
At present, there is no specific cure for this disease, and the clinical management mainly depends on supportive treatment.[9] Lopinavir-Ritonavir was once thought to be a promising medicine on COVID-19, but a recently published clinical trial found that the effect was limited.[10] As excessive immune response is an important reason for the progression of the patient's condition, the researchers turned their attention to immunosuppressants.[11] In a small sample clinical trial, the researchers found that hydroxychloroquine could improve the state of patients’ lungs and increase the probability of the virus turning negative.[12] However, the sample size of this study is small, and there may be some defects in the research design. In a case report, Remdesivir has shown good efficacy in patients with COVID-19, and larger clinical trials are currently under way.[13] Therefore, it is an important and urgent task to explore new therapeutic agents.
In the fourth edition of the diagnosis and treatment guideline of COVID-19 in China, Lianhuaqingwen capsule was listed as one of the recommended medicines.[14–16] In addition, traditional Chinese medicines (CHM), including Qingfei Paidu decoction, Huanglian Jiedu decoction etc., are also widely used in the adjuvant treatment of COVID-19. In terms of clinical research, many scholars have carried out clinical trials on the efficacy of CHM in treating COVID-19. However, these studies are only carried out in local areas, so they fail to provide definite evidence to prove the effectiveness of CHM. In this study, we aim to summarize the current evidence of CHM in treating COVID-19 through systematic review and meta-analysis . This study is necessary before further large-scale clinical studies being carried out. For clinicians, this study can provide some direction and guidance for clinical practice.
2 Methods and analysis
2.1 Study registration
This study has been registered at Open Science Framework (OSF, https://osf.io/ ) with a registration DOI: 10.17605/OSF.IO/H7GMU. This systematic review protocol is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA-P) checklist.[17]
2.2 Inclusion and exclusion criteria
2.2.1 Study design
Randomized controlled trials (RCTs) can provide evidence about efficacy of intervention, so they will be included in this systematic review. However, the outbreak of COVID-19 is an urgent public health event, and it is difficult to carry out RCTs, so non-randomized controlled trials will also be included in this study, although non-randomized controlled trials (non-RCTs) may be more biased than RCTs.
2.2.2 Participants
Participants with a laboratory-confirmed COVID-19 diagnosis will be included in this study. There will be no limitation about kits and detection methods. Also, there will be no restriction about age, sex, and severity of disease of participants.
2.2.3 Intervention
CHM in intervention group will be included. There will be no restrictions on the types, dosage forms, doses, and methods of use of CHM.
2.2.4 Outcomes
Since there are no core outcome sets for COVID-19, it is difficult to predefined what outcomes will be included in our study. In general, any outcome that can reflect the condition will be included in this study.
2.3 Study search
Three English database including PubMed, Embase, Cochrane Library Central Register of Controlled Trials, and 4 Chinese databases including China National Knowledge Infrastructure (CNKI) database, Wanfang Data Knowledge Service Platform, the VIP information resource integration service platform (cqvip), China Biology Medicine Disc (Sino Med) will be searched from its inception to April 1, 2020 without language limitation. Preprinted website including arXiv (http://arxiv.org/ ), BioRxiv (https://www.biorxiv.org/ ), F1000 (https://f1000.com/ ), and PeerJ Preprints (https://peerj.com/preprints/ ) will also be searched to find out more unpublished papers. In addition, Chinese Clinical Trial Registry (ChiCTR) and ClinicalTrials.gov will also be searched to find out ongoing research.
A search strategy of the combination of controlled vocabulary and text words will be adopted. Boolean operators will be used to concatenate search terms. This work will be conducted by 2 authors (ZH and MY) independently. The search strategy of PubMed is presented in Table 1 .
Table 1: Example of PubMed search strategy.
2.4 Study selection
EndNote X9 will be used by 2 researchers (ZH and MY) to screen the citations independently according to the predefined inclusion and exclusion criteria. Discrepancies between 2 authors will be solved by discussion with a third author (RY). A research flow chart will be drawn to show the whole process of research selection (Fig. 1 ).
Figure 1: Flow chart of study selection.
2.5 Data extraction
Data extraction will be conducted by 2 independent authors (MY and ZH) according to a prespecified form and checked by a third author (RY). The following data will be extracted: the first author's name, publication time, country, article title, article type, interventions in experimental and control group, course of treatment, severity of disease, number of patients in each group, ages and sex of patients, outcomes and adverse effect.
2.6 Risk of bias assessment
Different risk of bias assessment tools will be used according to different types of research. The risk of bias of RCTs will be conducted using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB2).[18] The Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool will be used to assess the risk of bias of non-RCTs according to Cochrane Handbook.[19]
2.7 Data analysis
Data analysis will be conducted using Stata 14.0, StataCorp, Texas, USA. The effect measure of binary variable will be expressed as risk ratio (RR) or odds ratio (OR) and 95% confidence interval (CI). For continuous variables, 95% CI and mean difference (MD) or standardized mean difference (SMD) will be used. The number needed to treat (NNT) will be calculated for the interpretation of results. Cochrane χ 2 and I 2 tests will be conducted to assess the heterogeneity analysis between studies. When P < .05 and I 2 > 50%, a random effect model will be used. When P > .05 and I 2 < 50%, then a fixed effect model will be used to calculate the effect size. The results of RCTs and non-RCTs will be analyzed and presented independently. Subgroup analysis will be conducted to explore the subgroup effects and investigate the source of heterogeneity. If there is a substantial heterogeneity and quantitative synthesis is not appropriate, the results will be presented in the form of tables and figures.
Publication bias and small-study effects will be evaluated by funnel plot and statistically investigated by Egger test with a P value boundary of .05.[20]
2.8 Ethics and dissemination
Meta-analysis is an analysis of previous research data and does not require ethical approval. The results of this study will be published in peer-reviewed journals.
3 Discussion
COVID is a global epidemic that has so far caused >700,000 confirmed cases and 30,000 deaths. At present, there is no effective treatment. Due to the long cycle and difficulties of new drug research and development, mining existing drugs has become the focus of research. Since there are some difficulties in carrying out clinical trials, this study will include both RCT and non-RCTs. Non-RCTs may introduce bias in the course of research, but it can provide evidence more conveniently. This means that we need to be more careful when interpreting non-RCT results. This research will comprehensively present the existing evidence of CHM in treating COVID-19, which will be of guiding significance for further research.
3.1 Amendments
If any modification is required, we will update our protocol to include any changes in the entire research process.
Author contributions
Conceptualization: Maoyi Yang, Zhipeng Hu, Rensong Yue.
Data curation: Maoyi Yang, Zhipeng Hu.
Formal analysis: Maoyi Yang, Zhipeng Hu.
Investigation: Maoyi Yang, Zhipeng Hu.
Methodology: Maoyi Yang, Zhipeng Hu.
Project administration: Rensong Yue.
Software: Maoyi Yang, Zhipeng Hu.
Visualization: Maoyi Yang, Zhipeng Hu.
Writing – original draft: Maoyi Yang.
Writing – review and editing: Rensong Yue.
References
[1]. The lancet infectious D. COVID-19, a pandemic or not? Lancet Infect Dis 2020;20:
[2]. Goyal P, Choi JJ, Pinheiro LC, Schenck EJ, Chen R, Jabri A, et al. Clinical Characteristics of Covid-19 in New York City. The New England journal of medicine. 2020. DOI:10.1056/NEJMc2010419.
[3]. Wu C, Chen X, Cai Y, et al. Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China. JAMA Intern Med 2020;doi: 10.1001/jamainternmed.2020.0994.
[4]. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054–62.
[5]. Huang C, Wang Y, Li XW, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497–506.
[6]. Chen N, Zhou M, Dong X, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020;395:507–13.
[7]. Hellewell J, Abbott S, Gimma A, et al. Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts. Lancet Glob Health 2020;8:e488–96.
[8]. Wang T, Du Z, Zhu F, et al. Comorbidities and multi-organ injuries in the treatment of COVID-19. Lancet 2020;395:PE52.
[9]. Matthay MA, Aldrich JM, Gotts JE. Treatment for severe acute respiratory distress syndrome from COVID-19. Lancet Respir Med 2020;doi: 10.1016/S2213-2600(20)30127-2.
[10]. Cao B, Wang Y, Wen D, et al. A trial of Lopinavir-Ritonavir in adults hospitalized with severe Covid-19. N Engl J Med 2020;doi: 10.1056/NEJMoa2001282.
[11]. Mehta P, McAuley DF, Brown M, et al. COVID-19: consider cytokine storm syndromes and immunosuppression. Lancet 2020;395:1033–4.
[12]. Gautret P, Lagier JC, Parola P, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents 2020;105949.
[13]. Holshue ML, DeBolt C, Lindquist S, et al. First case of 2019 Novel Coronavirus in the United States. N Engl J Med 2020;382:929–36.
[14]. Luo H, Tang QL, Shang YX, et al. Can Chinese medicine be used for prevention of Corona Virus Disease 2019 (COVID-19)? A review of historical classics, research evidence and current prevention programs. Chin J Integr Med 2020;1–8.
[15]. Ren JL, Zhang AH, Wang XJ. Traditional Chinese medicine for COVID-19 treatment. Pharmacol Res 2020;155:104743.
[16]. Runfeng L, Yunlong H, Jicheng H, et al. Lianhuaqingwen exerts anti-viral and anti-inflammatory activity against novel coronavirus (SARS-CoV-2). Pharmacol Res 2020;104761.
[17]. Moher D, Shamseer L, Clarke M, et al. Preferred reporting items for
systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev 2015;4:1.
[18]. Krentz NAJ, Gloyn AL. Insights into pancreatic islet cell dysfunction from type 2 diabetes mellitus genetics. Nat Rev Endocrinol 2020;16:202–12.
[19]. Sattar N, McMurray JJ, Cheng AY. Cardiorenal risk reduction guidance in diabetes: can we reach consensus? Lancet Diabetes Endocrinol 2020;doi: 10.1016/S2213-8587(20)30062-0.
[20]. Song F, Gilbody S. Bias in meta-analysis detected by a simple, graphical test. Increase in studies of publication bias coincided with increasing use of meta-analysis. BMJ 1998;316:471.