This systematic review is registered inthe Prospective Register of Systematic Review (PROSPERO) database (CRD42020179205). We formulated this protocol in accordance with the Preferred Reporting Item for Systematic Review and Meta-analysis - Protocol (PRISMA-P) statement (Additional file 1).
We will include clinical practice guidelines, consensus statements and guidance documents published by any advising body or healthcare organization since December 2019, which provide information on the use of traditional Chinese herbal medicine therapy for COVID-19 patients.
Recommendations forpatients diagnosed with COVID-19 pneumonia withrecognized diagnostic criteria will be included (such as positive real-time fluorescent Reverse Transcription-Polymerase Chain Reaction of respiratory or blood samples for new coronavirus nucleic acid, highly homologous of the respiratory specimen or blood specimen sequenced to novel coronavirus). There will be no restrictions with respect to age, gender or ethnicity.
We will include recommendations for Chinese herbal medicine involving extracts from herbs, single or mixture herbal formulas, and Chinese patent medicine, regardless of their forms (e.g. pill, powder, oral liquid etc.).
We will exclude old versionsof guidelines or consensus statements published by a single advising body or healthcare organization.
Databases and search strategy
We will search for guidelines, expert consensuses and policy documents published since December 2019 in the following electronic databases: PubMed, Embase, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP), and Wanfang database (Wanfang Data). We will also search other sources of guidelines including: The National Guideline Clearinghouse (NGC), Guidelines International Network (GIN), National Institute for Health and Clinical Excellence (NICE), Scottish Intercollegiate Guidelines Network (SIGN) and WHO. We will use search strategies that combine termsrelating to novel coronavirus, traditional Chinese medicine and guideline. The search strategy for PubMed is described in Additional file 2, and suitably modified search strategies will be applied to the other electronic databases. We will also search grey literature via websites of governments or organizations. No language restrictions will be applied.
We will upload search results into EndNote X9 reference management software. We will filter and remove duplicate references. Two independent reviewers (YXL and DLZ) will screen titles and abstracts to identify potentially eligible documents, which will be retrieved in full text for final review. Any disagreements will be discussed and arbitratedby a third reviewer (YGZ).
We will design a data extraction form based on characteristics of included guidelines and consensuses. In order to achieve consistency (at least 80%) in extracted items, we will pilottest the data extraction form with data extractors using a sample of eligible documents. Results of this pilot extraction will be discussed among review authors and extractors before finalizing it. Data extraction will beconducted independently by two reviewers (JL and YZ), and will include the following data: (1) characteristics of guidelines: name, type, source and date; (2) stage of disease; (3) syndrome differentiation; (4) treatment principle; (5) recommended formula; and (6) recommended Chinese patent medicine etc. Disagreements will be resolved by discussion among the review team.
We will evaluate the methodological quality and reporting quality of the included guidelines using the Appraisal of Guidelines for REsearch& Evaluation (AGREE) II tool and Reporting Items for Practice Guidelines in healthcare (RIGHT) statement, respectively. In order to achieve consistency of at least 80% in the quality assessments, the assessors will pre-assess a sample of eligible documents and discuss their assessment among review authors and assessors. Afterthat, two independent reviewers (YXL and JL) will appraise the quality of included guidelines.Discrepancies will be discussed and resolved among the reviewers.
With the information extracted from the included guidelines, we will summarize the recommendations made for traditional Chinese herbal formulae and Chinese patent medicine for COVID-19 patients. The recommendations of prescriptions for different stages and syndrome differentiations of COVID-19 will also be summarized. These findings will be discussed in light of the strength and quality of these recommendations with reference to the results of AGREE II and RIGHT tools.