In response to the COVID-19 pandemic government restrictions were employed in Ontario, Canada to reduce infection rates. This study sheds light on several critical aspects of the COVID-19 pandemic’s impact on a cohort of community-dwelling adults in Ontario, Canada. We observed significant associations between participant demographics and reported illnesses, with older individuals and those with pre-existing conditions experiencing more severe illness symptoms and greater associated activity limitations. Moreover, our findings highlight the substantial behavioural changes triggered by the pandemic declaration, with participants across all age groups and health statuses adopting lower exposure risk behaviours. Furthermore, our analysis underscores the responsiveness of exposure risk to government-imposed restrictions, with increased stringency coinciding with decreased exposure risk among participants6, 21. Notably, the observed decline in adherence to these measures over time suggests the presence of "pandemic fatigue," with diminishing perceived risk associated with COVID-19. These findings collectively emphasize the nuanced interplay between demographic factors, government interventions, and individual behaviours in shaping the trajectory of the pandemic within our community.
The incidence of communicable infections during the early stages of the COVID-19 pandemic was very low due to social distancing behaviours28. In pre-pandemic times, older adults had, on average, 1 upper respiratory tract infection a year29 and healthy, younger adults had 2–3/year, proportionate to their number of social contacts30. We found that only half of all respondents reported any illness (communicable or non-communicable) over the study period, with younger adults (≤ 39) reporting 1.66 illnesses, middle-aged adults (40–69) reporting 1.34, and older adults (≥ 60) reporting 0.75 on average. Of these, the vast majority were not upper respiratory tract infections suggesting government restrictions reduced the incidence of infection during the study period. When participants did report an illness, we found that older adults and individuals with pre-existing health conditions reported more severe symptoms. COVID-19 infections (as detected by serology and/or symptom reports) were low and consequently we were not able to attribute infection to differences in exposure risk; however, all the COVID-19 infections were in younger adults (< 60 years), consistent with local epidemiology21.
Consistent with previous reports22,23, we found that compliance with government restrictions was high and individual exposure risk was low during this period. We found that across all demographics, changes to pre-pandemic behaviours significantly lowered individuals’ exposure risk early in the pandemic; however, over time, government restrictions had a diminishing effect on exposure risk. Waning compliance to restrictions, even if the number of infections remained high, has been reported elsewhere24. As an example, the majority of UK adults surveyed from April 2020 to February 2021 maintained high levels of compliance during the two COVID-19 waves during that period25. However, 15% of participants reported reduced levels of compliance during the second wave25. This may indicate that individuals experiencing repeated cycles of government restrictions become less compliant over time. Contrary to our initial hypothesis, we found that vaccination status did not significantly alter exposure risk among participants. The association between vaccination status and adherence to social distancing measures and other restrictions is inconsistent in other reports 26,27.
Demographic factors (e.g., age and sex) are known to impact compliance with government restrictions: women and older adults have reported higher levels of compliance with recommended and mandated health measures10, 11, 12, consistent with our finding of reduced exposure risk associated with these populations. We also report a significantly lower exposure risk in participants with pre-existing health conditions known to increase the risk of severe COVID-19 infection (e.g., chronic respiratory disease). Conflicting data exist on the effect of health status on physical distancing behaviour. Coroiu et al. (2020) observed from March to April 2020 that individuals with pre-existing conditions in countries with police-enforced isolation measures were more likely to interact with family members outside of their households12. In contrast, Hills and Eraso (2021) observed that in May 2020 in the UK, a country with relatively less strict physical distancing measures12, individuals with a pre-existing condition were more likely to adhere to physical distancing measures13. Potential explanations for these contrasting results may be an increased sense of isolation in countries with strictly enforced measures12 or more comprehensive at-home public services in the UK13, which may have decreased and increased compliance, respectively.
Non-pharmaceutical interventions, including masking, have substantially reduced the number of cases, hospitalizations, and deaths due to COVID-19 in Canada31,32. Understanding the factors associated with compliance may inform implementation in future public health emergencies.