Population-wide Observational Study in Brazil: Prophylactic Use of Ivermectin Reduces COVID-19 Mortality, Hospitalization & Infection

Lucy Kerr, a Brazilian physician, participated in an Ivermectin summit hosted by TrialSite. Kerr and four other medical researchers, two affiliated with Brazilian academic medical centers and one from a Cuban biotech institute were involved in the study of the efficacy of the generic, regulatory approved antiparasitic drug in three different municipalities in Brazil covered by TrialSite back in September 2020. Most recently, Dr. Kerr and colleagues posted the results of a citywide prevention program using ivermectin, implemented in Itajai in the south of Brazil. The prospective, observational study analyzed citywide COVID-19 data between July 2020 to December 2002. The study logistics of instructional review board approval and registry data analysis occurred retrospectively due to the urgent pandemic conditions at the time.

TrialSite emphasizes this research hasn’t been peer-reviewed yet and shouldn’t be cited as medical evidence. This media platform focuses on medical research and these results require further verification. The study data derives from a public health program in response to COVID-19 in the municipality of Itajai in Santa Catarina, Brazil. This city has nearly 285,000 residents.

The Study

As reported in the group’s manuscript posted on ResearchGate, the Brazilian observational retrospective study centered on population-level data associated with the Brazilian municipality’s public health program. A total of 220,517 subjects were included in the analysis including:

Group%133,051 regular ivermectin users60.3%87,466 non-ivermectin users39.7%

Study Hypothesis

Did ivermectin have a positive impact on subsequent COVID-19 infection and mortality rates?

Results

Setting up various categories for analysis, the study team compared ivermectin use with nonuse based on several cohorts (e.g., age, sex, comorbidities, etc.) while both employing, in some cases, patient propensity score matching or “PSM,” a statistical matching technique that attempts to estimate the effect of a treatment or other intervention by accounting for the covariates that predict receiving the treatment. This method is used in a bid to reduce bias in observational studies associated with confounding variables that are present in results.

The study team reports in what is still non-reviewed data the following:

  • Out of two study cohorts of 3,034 COVID-19 infected patients, the regular use of ivermectin led to a 68% reduction in COVID-19 mortality 25 (0.8%) versus 79 (2.6%) among ivermectin non-users—mortality rates were analyzed both with and without PSM. The reported risk ratio (RR) equaled 0.32; 95% confidence interval, 0.20-0.49; p < 0.0001.

  • Adjusting for residual variables, Kerr and team report a mortality reduction at 79% (RR, 0.30; 95%CI 0.19 – 0.46; p < 0.0001).

  • A 56% reduction in hospitalization rate (44 versus 99 hospitalizations among ivermectin users and non-users respectively—RR, 0.44; 95% CI, 0.31-0.63; p < 0.0001).

  • Adjusting for residual variable s they reported a reduction in hospitalization at 67% (RR, 0.33; 95%CI 023 – 0.66; p < 0.0001 ).

Conclusion

Dr. Kerr and colleagues report that based on their data, the large, propensity-matched study verifies that regular use of ivermectin as a prophylactic agent was associated with a significant reduction in COVID-19 infection, hospitalization, and mortality rates.

Limitation

This study isn’t yet peer-reviewed, and hence, shouldn’t be used to cite medicinal evidence. Moreover, observational studies done retrospectively carry less weight than randomized, controlled studies. 

Comment

TrialSite notes that over 70 ivermectin studies have been concluded around the world, with a great majority of them evidencing some positive impact. In the West, (e.g., North America, Europe, Australia, etc.) medical establishments have discounted the numerous ivermectin studies and focused more on a couple of the studies that either generated neutral findings or in one case had what looked to be improper data manipulation. 

It’s astounding, however, that the positive data is uniformly discounted as not relevant.

Lead Research/Investigator