Computer Science

The number of deaths in Ontario rose significantly in 2020, the first year of the COVID-19 pandemic – not really a surprise. But data show that the excess mortality was due not just to coronavirus but to other, non-COVID causes as well, and that was unexpected. And here’s what else is surprising: In Ontario, as in many other provinces and territories, reporting of mortality data is routinely delayed by several months due to verification requirements for official recordkeeping of vital statistics. If the full impact of COVID-19 is to be understood, it is crucial to find a reliable source of real-time data on deaths, and for now, a Western undergraduate student is helping fill the information gap. Gemma Postill spends her weekends analyzing cremation records that provide Ontario’s Chief Coroner, Dr. Dirk Huyer, with robust, real-time estimations of provincial mortality. Her analyses support the understanding that the COVID-19 pandemic has impacted mortality rates in Ontario both directly and indirectly. “Cremation records accurately estimate provincial excess mortality on an interim basis while official records are being processed,” said Postill, a research assistant in Western’s Computational Convergence Lab led by Mark Daley. “Our findings highlight both the benefit and need for real-time mortality information.” In Ontario, certification by a coroner is required before cremation can occur. Since 2017, under Huyer’s leadership, this process has been digitized, resulting in an electronic cremation record – and a treasure trove of data for Postill to mine. As a result, she found a 12.8 per cent rise in the number of cremations in 2020 compared with the annual average between 2017 and 2019, while there was no change in the proportion of cremations versus traditional burials “Initially, when we saw an increase in the number of cremations, we couldn’t rule out that more people were getting cremated because they couldn’t have a formal funeral or a celebration of life due to physical distancing restrictions,” said Postill. “But that wasn’t the case.” Using data from Statistics Canada, which is now available to the end of December, 2020, Postill confirmed that the percentage of cremations has remained remarkably consistent during the pandemic. This finding furthers the evidence that cremation records provide an accurate, real-time estimate of all causes of mortality. “About 70 per cent of Ontario residents are cremated, and that hasn’t changed during the pandemic,” said Postill. And since nearly all (99 per cent) cremations in Ontario take place within three weeks of death, she obtained a timely and robust source of mortality data that can be used while waiting for official statistics to become available. Postill said that confirmed COVID-19 deaths identified in the cremation records did not account for all the excess mortality observed. In the first wave, most of the excess mortality occurred in long-term care, with a smaller number in personal residences. While the number of deaths in long-term care returned to normal, the number of deaths in personal residences accounted for most of the excess in the later waves of the pandemic, said Postill, who will be attending University of Toronto in the fall for an MD/PhD program. “Gemma is an incredible student and an important member of our lab. Her data analysis is the closest thing we have to real-time mortality monitoring in Ontario,” said Daley, Western’s special advisor to the president on data strategy. “She’s stepped up, working every weekend for more than a year now, to fill a significant gap in our health-care system and provided lifesaving data to the coroner and the provincial government during a global pandemic. It’s remarkable.” Daley is currently on a three-year secondment as CIFAR vice-president (research).