Impact of the COVID-19 pandemic on health services utilisation and mortality in Ontario, Canada: an interrupted time series analysis.

BACKGROUND

This study explores changing patterns of healthcare utilisation for chronic diseases during the COVID-19 pandemic in Ontario, Canada. It compares prepandemic and pandemic morbidity and mortality, focusing on physician and emergency department visits, hospitalisations for anxiety, depression and chronic diseases, as well as all-cause mortality rates.

METHODS

We constructed a cohort of 2 950 384 adults (18+ years), using administrative health databases, who were living in Ontario, Canada, between the period of January 2017 and March 2023 and recorded the number of visits each individual had in the follow-up period related to chronic conditions. The data were then analysed using an interrupted time-series design to observe changes from before compared with during the pandemic in (1) monthly physician or emergency visits and hospitalisations and (2) monthly all-cause deaths. The exposure in this study was the onset of the COVID-19 pandemic in Ontario, Canada.

RESULTS

In the prepandemic period, mean monthly PCR-tested visits in Ontario were 364 880, with a steady increase of 1210 visits per month. During the initial phase of the COVID-19 pandemic, there was a decline in physician visits and hospitalisations for chronic diseases. This trend changed, leading to a significant rise in visits that peaked in March 2021, increasing by 1690 visits monthly. From 2022 onwards, visits saw a notable decline, decreasing by 6830 per month (p<0.05), reflecting reduced healthcare utilisation in the later pandemic phases.

CONCLUSIONS

The COVID-19 pandemic caused significant fluctuations in healthcare utilisation in Ontario. These changes suggest increased risks of missed diagnoses and delayed care, impacting morbidity and mortality. The results emphasise the importance of adaptable healthcare systems and strong pandemic preparedness to maintain care continuity, especially for chronic disease management, during resource-limited periods.