As we have progressed through multiple waves of the COVID-19 pandemic, the Ontario provincial government used four lockdowns to slow the spread of the virus in 2020.
Lockdowns have no doubt saved countless lives from COVID-19, but what were the unintended consequences? Researchers at the University of Toronto have conducted the largest known study worldwide of non-natural deaths (including homicides, suicides, and accidents) to measure the effects of lockdowns in Ontario. “Over 4,000 COVID deaths were reported in 2020, but we also saw over 1,500 more accidental drug-related deaths than predicted – the sheer magnitude of this effect was unanticipated, but clearly must be considered by policymakers moving forward,” says study lead Dr. Jennifer M. Dmetrichuk.
An Assistant Professor in the Department of Laboratory Medicine and Pathobiology and a Forensic Pathologist with the Ontario Forensic Pathology Service (OFPS), Dmetrichuk was surprised by the results of the study.
“There was so much speculation about whether the lockdowns had impacted manners of death”, she explains, “Whether reports of increased domestic violence led to more homicides, fewer cars on the road resulted in fewer fatal car accidents, or the mental health burden had resulted in more suicides - we wanted to use a scientifically and statistically sound approach to see what actually happened, with the aim of providing evidence to government officials, public health, and policymakers to assist in their decision-making”.
Co-investigator, Dr. Jeffrey Rosenthal, Professor of Statistics at the University of Toronto, brought statistical expertise to the study, identifying pre-existing trends over the past decade in Ontario, and highlighting deviations from these trends during the various stages of lockdowns in 2020. The results are interpreted and reported reflecting the American Statistical Association's (ASA) statement on statistical significance and p-values, and current recommendations (i.e. p-values interpreted as a spectrum versus dichotomous significance determined solely based on using a specified p-value). This is of particular importance in the context of this study, as the ASA states that scientific conclusions and business or policy decisions should not be based only on whether a p-value passes a specific threshold.
The Office of the Chief Coroner and the Ontario Forensic Pathology Service (OCC-OFPS) investigate any sudden deaths in the province and categorize them into five manners of death: homicide, suicide, accidental, natural, or undetermined. Dr. Dmetrichuk and her collaborators reviewed 197,966 deaths occurring between 2009-2020, using 77,655 for the study which had a manner of death that was homicide (2,443), suicide (16,425), or accident (58,787).
It was in the category of accidental deaths that Dmetrichuk and her team found the most surprising results.
The biggest impact of lockdowns was on accidental deaths due to drug overdoses. A trend already on the rise due to the opioid crisis across North America, the number of deaths observed in 2020 was substantially higher than anticipated.
“This highlights the need to consider the impacts of public health interventions that are meant to protect the population as a whole but may have unintended adverse effects in sub-populations. We need to be able to identify those at risk and put in place safeguards to mitigate against such effects in the event of further whole-population public health measures.”
Motor vehicle collision-related fatalities in Ontario show a slight decreasing trend over the past decade, possibly due to law enforcement, safe driving campaigns, refined vehicle design, or improved roadways and signage. “In the first stage of the lockdown, we anticipated motor vehicle-related fatalities would decrease due to the stay-at-home order, but the effect was very minimal,” says Dmetrichuk, “the presumed protective effect of having fewer vehicles on the road may have been offset by increases in motor vehicle-related deaths due to unsafe driving practices, such as driving under the influence of drugs/alcohol or speeding and stunt driving on emptier roads”.
Homicides were not substantially impacted by the lockdowns, with no change in the slight upward trend over the last decade, though gun violence is on the increase in Ontario. The data showed that increased domestic violence rates in some jurisdictions following stay-at-home orders may not have translated into increased homicide rates in Ontario during 2020. However, the long-term impact of the pandemic remains to be seen.
Contrary to perceptions, suicides decreased in the first stage of the lockdown, then returned to baseline rates, but saw no increase above expected based on already existent trends. “Although suicide rates have been steadily increasing in Ontario and need to be addressed, the lockdowns did not impact them in the way we anticipated,” says Dmetrichuk. “We speculate that there may have been positive mental health impacts of studying or working from home that may have helped initially. However, the long-term impact needs to be studied as we enter the third year of the pandemic and effects on mental health evolve.”
Dmetrichuk and her team are already looking at manner of death data for 2021. “The results for 2020 were so unexpected that I can’t predict what the next set of data will tell us. It will be interesting to see if trends do change over time”. In the meantime, the team hopes that their results will be part of deliberations as government officials and policymakers continue to consider the benefits and costs associated with the public health response to the COVID-19 pandemic.
