How and when should schoolchildren return to in-person learning? Are kids in schools driving community transmission of COVID-19, or is it the other way around? These questions are difficult to answer and researchers at Western University say policy makers are lacking rigorous data to inform their decisions.
This uncertainty could be clarified by conducting cluster randomized trials when students return to class, according to a new publication from an international team of experts co-led by Dr. Charles Weijer, professor at Western University.
In Ontario, some students will return to class in late January after learning from home since December, while others in areas with higher rates of community transmission, will remain learning online until at least February. Weijer points out that without randomly selecting which schools will remain closed and which will open, they won't be able to determine rigorously whether schools are driving community infection rates or vice versa.
Cluster randomized trials, which would mean randomly keeping some schools closed and opening others to in-person learning, could create a body of evidence to help policymakers make the right decisions in future, the researchers said in a paper published in the journal Clinical Trials.
"Our paper highlights the importance of doing this study, and that the ethical challenges to doing such a trial are not insurmountable," said Weijer, professor at Western's Schulich School of Medicine & Dentistry and the Faculty of Arts and Humanities and an expert on the ethics of randomized trials. "We've seen a huge shift in clinical medicine whereby most treatments that patients are prescribed are supported by high-quality evidence. When we're dealing with public policies around public health or education, there isn't that same robust evaluation of these policies."
The pandemic's rapid onslaught required public health policies to be put into practice quickly, and governments operated on the basis of an abundance of caution and a need to act, the paper noted.
As the second and third waves took hold, schools across the globe closed their doors to in-person learning, but this varied from country to country and region to region.
Reopenings will provide an opportunity to answer questions about the impact of the closures on transmission of the virus, as well as how restrictions can be safely lifted, the researchers said.
Dr. Charles Weijer of the Schulich School of Medicine & Dentistry at Western University
"As COVID-19 cases and deaths ebb and flow around the world, the question of when and how to withdraw public health policies is pressing," said co-author Karla Hemming, a biostatistics professor from the University of Birmingham's Institute of Applied Health Research. "Many regions face new waves of outbreaks and new lockdowns. Whether and when schools can reopen and stay open will continue to be a question of upmost importance, but policymakers are left to make such decisions in the absence of rigorous evidence."
Swedish schools remained open for under-16s throughout the pandemic, while in Denmark, Germany and Norway schools reopened after a period of closure. Italy and Spain chose to keep schools closed until last fall, but schools in Austria, the Czech Republic and Russia have at times closed. Variability is also seen within the United States and Canada.
The reopening of primary schools in Quebec was associated with relatively few new cases, while in Israel some schools had to reclose because of outbreaks.
Public officials offered varied justifications for their decisions, with some relying on local test positivity rates and others focusing on numbers of new cases within schools.
The impact of school closures is exceptionally broad and serious, said Weijer. "That to me is the real case for making sure that the reopening of schools is guided by the most rigorous evidence.
"It's not just a matter of keeping our kids safe from COVID-19 or keeping our community safe from potential drivers of rates of infection in the community. It's also the burden on an entire generation of children in terms of their educational experience, their socialization, and on parents as well, who may not be able to return to work or may have to hire child care."
The paper, which included collaborators from Harvard University and the University of Pennsylvania, said cluster randomized trials are well suited to the rigorous evaluation of public health policies. It highlighted five aspects of trial design:
- Running such a study should only be considered when community transmission is under control and the health system has sufficient capacity;
- Since the main interest is in community transmission of the virus, the study would include many municipalities or regions.
- Entire regions (including all schools therein) would be randomized to either reopen or remain closed;
- Those reopening should operate under precautions including social distancing, mask wearing and possibly even testing. Teachers and children who are clinically extremely vulnerable should be allowed to stay home;
- For schools that remain closed, the associated burdens for children and parents require careful consideration.
