Overview of COVID-19 Research Databases

Database Inclusion

As of March 9th, 2021 35 websites met our criteria for inclusion in the web directory. Out of those 35 websites, 18 (51%) have a study database, 13 (37%) have a results database, and 15 (43%) perform results appraisals (Figure 1). Three websites (8%) contain all three categories – L*OVE COVID-19, Cochrane Coronavirus, and Covid-19 Living NMA. 


Legend: Inclusion criteria. All sites are dedicated to COVID-19 research. Sites in the gray portion of the Venn diagram publish a database of studies. Sites in orange publish a database of study results. Sites in green publish appraisals of evidence.


Study Type

For websites with either a study or a results database (35), all but four include both interventional and observational studies. Four websites include only interventional studies in their databases. 


For the 35 websites included in the directory, 32 include either studies, study results or results appraisals of vaccines, 31 included drug treatments, 30 included therapeutic interventions, 24 included public health measures, and 22 included diagnostics. 

Sponsor and Location 

Twenty of the 35 websites (57%) are privately sponsored, and twenty-two (63%) are based primarily out of the United States or the United Kingdom. 

Target Audience 

Most websites describe their intended audiences as including clinicians and researchers. 

Data Source 

16 out of 18 websites with study databases pull study information from Clinicaltrials.gov and 11 pull study information from ChiCTR. Twelve out of 18 websites with study databases pull study information from WHO. The majority of these websites generally list study recruitment status (10 of 18) and 14 produce overview statistics of new and ongoing research studies. PubMed/MEDLINE and MedRxiv/BioRxiv are the most frequently cited data sources for study results (14 and 11 out of 15 websites, respectively), followed by WHO and publisher databases (10 and 10, respectively), Clinicaltrials.gov (9) and press releases (3). 

Update Frequency 

Most websites update their studies and results databases weekly or monthly. 

Number of Studies and Studies Results 

Depending on the topics and study designs covered, the number of studies per database varies between less than 100 to over 6000, and the number of study results ranges from less than 100 to over 300,000. 

Results Appraisal 

The types of results appraisal performed by websites includes narrative commentary (10 of 15 sites with results appraisal), results quality assessment (9), and summary statistics (3). Seven websites produce meta-analyses or systematic reviews, and 2 of these 7 websites perform cumulative meta-analyses. 

Communication Platforms 

Twitter is the most common communication platform used to connect audiences to websites (24 out of 35), followed by email newsletters and Facebook (13 and 14 out of 35 respectively). Additional features of some websites include information on expanded access studies, geographic mapping of studies, and production of COVID-19 webinars and podcasts.