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Systematic reviews highlight research opportunities

Illustration of meta-analysisNew research from the University of Guelph’s Ontario Veterinary College (OVC) is highlighting the value of systematic reviews and identifying opportunities for further discovery in antimicrobial stewardship. 

Prudent and effective use of antimicrobials is critical to minimize the prospect of bacteria becoming resistant to the medicine used to treat them. Antimicrobial resistance is one of the biggest challenges of the 21st century across human and veterinary medicine. 

“The studies in this journal issue provide a very broad look at an important area across livestock agriculture, and provides an important baseline helping researchers to identify gaps in current knowledge around antimicrobial use in food producing animals and opportunities to enhance future research in this area,” says Prof. Jan Sargeant.

Sargeant, along with Prof. Charlotte Winder, both in OVC’s Department of Population Medicine, authored 14 articles describing specific research findings from these reviews. Annette O’Connor, a professor at Michigan State University's College of Veterinary Medicine, is also a key collaborator on this research. 

The papers are featured in a special issue of Animal Health Research Reviews, published in February 2020. The journal provides an international forum for published reviews and commentaries on all aspects of animal health.

In the systematic reviews, researchers focused on two areas: studies looking at the efficacy of antibiotics used to prevent diseases in four livestock groups (beef, dairy, poultry and swine) and those looking at the efficacy of non-antibiotic management practices used to try to prevent these diseases. 


In the illustration: Meta-analysis draws a network using direct comparisons from studies and then estimating indirect comparisons between them. For example, in this illustration, if one study compares A to B and another compares A to C, the network can compare B to C based on the information it has. 


“Veterinarians and livestock producers are already looking at much more nuanced ways to apply antibiotics to reduce overall use, as well as on-farm management practices to help prevent disease,” says Winder. “This research identified where more fundamental science is needed to support these efforts.”

Systematic reviews and network meta-analysis provide a rigorous scientific means to evaluate research. “It is the ideal technology for this particular research question,” says Sargeant. 

Used for more than two decades in human healthcare, systematic reviews increasingly are making important inroads into veterinary medicine. 

They provide a transparent, comprehensive summary of current knowledge and, as this work illustrates, can help researchers recognize gaps in knowledge and identify questions that need to be answered with future research. Powerful techniques such as network meta-analysis take the process one step further, allowing researchers to harness information to determine the comparative effectiveness of many different interventions for preventing illness.

“However, our research shows that we could do a better job of linking information from clinical trials studying various preventive strategies. This would add to our overall knowledge and build a better body of evidence about their efficacy,” says Sargeant.

By identifying common interventions or treatments that can be used across multiple clinical trials, “we can better link our evidence and make more powerful decisions,” she adds. 

The researchers also emphasize replicating results and using consistent measures for outcomes are key to building scientifically-validated research. 

Winder notes researchers need to be supported in replicating research questions, in order to ensure results are valid. 

“This builds a strong body of evidence to help veterinarians and producers with prudent treatment decisions,” she adds. 

Sargeant and Winder hope the study results will build awareness among researchers and research funders for opportunities to help them better direct their resources. 

But the ultimate beneficiaries will be livestock producers and veterinarians by providing them access to strong evidence-based data to aid in treatment decisions. 

The research was conducted with support from The Pew Charitable Trusts, a non-profit research and public policy organization in the U.S. Additional work was supported by the Ontario Agri-Food Innovation Alliance and Ontario Ministry of Agriculture, Food and Rural Affairs.