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Evaluation of the initial response in clinical trials efforts for COVID-19 in Brazil


  • Tatiane Bomfim Ribeiro Universidade de São Paulo
  • Talita Aona Mazotti Universidade de São Paulo
  • Nayara Aparecida de Oliveira Silva Universidade Federal de São Paulo
  • Airton Tetelbom Stein Universidade Federal de Ciências da Saúde de Porto Alegre
  • Fredi Alexander Diaz-Quijano Universidade de São Paulo
  • Daniela Oliveira de Melo Universidade Federal de São Paulo



Covid-19, Clinical Trials, Resource Allocation, Efficacy, Brazil, Clinical Protocols


Objective: To describe the methodological characteristics and good research practices of the intervention studies for COVID-19 developed in Brazil in the first months of the pandemic. Method: A review in the CONEP-COVID bulletin (05/28/2020) and the International Clinical Trials Registry Platform,, ReBEC was conducted to identify drug-type, biological therapy or vaccine intervention studies registered in Brazil. The studies were evaluated for methodological characteristics and power for different magnitudes of effect. Results: 62 studies were included, 55 identified on the CONEP website and seven on a registration database. Several interventions are being tested: chloroquine/hydroxychloroquine, azithromycin, plasma convalescent, tocilizumab, sarilumab, eculizumab, vaccine, corticoids, anticoagulants, n-acetylcysteine, nitazoxanide, ivermectin, lopinavir/ritonavir, etc. By May 2020, 22 research protocols were published in a protocol registry database, 82% were randomized clinical trials and 59% had adequate control group. However, 59% were not masked and only 24% included patients with positive test with diagnostic accuracy. Most of the studies would have power >80% just to identify large effect sizes. In a prospective follow-up, until July 21st/2020, 60% of the studies available at CONEP were not registered in the ICTRP/ReBEC/ClinicalTrials platforms. Conclusion: The interventions evaluated during the Brazilian research response reflect international initiatives, but with a different distribution, a larger proportion of studies asseessed hydroxychloroquine/chloroquine. Limitations in methodological design and sample planning represent challenges that could affect the research outreach.


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How to Cite

Ribeiro, T. B. ., Mazotti, T. A. ., Silva, N. A. de O., Stein, A. T. ., Diaz-Quijano, F. A. ., & Melo, D. O. de . (2020). Evaluation of the initial response in clinical trials efforts for COVID-19 in Brazil. In SciELO Preprints.


Health Sciences