Revised on 29 March 2021, 11:10 a.m.
Any substantive changes in this HillNote that have been made since the preceding issue are indicated in bold print.
(Disponible en français : Résultats cliniques dans différentes populations au Canada lors de pandémies)
On 11 March 2020, the World Health Organization (WHO) characterized the outbreak of COVID-19, the disease caused by the novel coronavirus (SARS-CoV-2), as a pandemic. As everyone initially lacks immunity to the virus, all Canadians risk contracting COVID-19. However, certain groups may face greater health risks than others because of underlying health conditions, occupational risks, the environment in which they live and other factors. This HillNote examines the potential impact of personal, social, economic and environmental factors, as well as the interactions among these factors, on health outcomes during pandemics.
The guiding principles for the Government of Canada’s response to COVID-19 are based on lessons learned from previous public health emergencies, including the Severe Acute Respiratory Syndrome (SARS) outbreak in 2003. The federal response to COVID-19 includes considerations of health outcomes in vulnerable groups such as seniors and remote populations.
Determinants of Health
Personal, social, economic and environmental factors – known as the determinants of health – interact with one another and influence the health of individuals and populations. Studies suggest a link between the determinants of health and the susceptibility to and/or the severity of illness, including during pandemics. Selected determinants of health discussed in this HillNote include:
- biology and genetics;
- access to health services;
- physical environment;
- health literacy; and
- income, employment and working conditions.
Biology and Genetics
Biology and genetic makeup play a role – although it is not certain to what degree – in an individual’s reaction to a virus:
- The majority of people who die from seasonal influenza in Canada are seniors, often with chronic medical conditions. In contrast, during the 2009 H1N1 pandemic, younger age groups (including those who were otherwise healthy) were most affected, requiring hospitalization and intensive care.
- During the SARS and Middle East Respiratory Syndrome epidemics, WHO data indicate that males had worse health outcomes than females. During the H1N1 pandemic, females experienced greater critical illness than males in Canada.
- Certain groups, such as pregnant women and people with pre-existing conditions, were at heightened risk of developing complications from H1N1 in Canada.
For the COVID-19 pandemic, global data suggest that although the disease is found in all age groups, adults over 60 years of age are at the greatest risk of experiencing severe illness. In Canada, 19.9% of reported cases* (as of 26 March 2021) are among individuals 60 years of age and older, and these cases represent the highest proportion of hospitalizations (70%) and intensive care unit admissions (65%).
Data from selected countries suggest higher rates of death from COVID-19 among males than females. However, as of 26 March 2021 in Canada, females represent 51.1% of reported COVID-19 cases and 51% of deaths; whereas males represent a higher proportion of hospitalizations (53%) and intensive care unit admissions (63%).
It is not known to what extent biology and genetics or other determinants of health are responsible for the differences in health outcomes among males and females (see discussion under “Physical Environment”).
In addition, as of 15 April 2020, 75% of patients hospitalized with COVID-19 in Canada had one or more pre-existing conditions, including respiratory disease, cardiac disease, and diabetes.
While pregnant women and their babies are at increased risk of adverse heath outcomes during influenza infections, early data and research on COVID-19 and pregnancy outcomes suggest that “maternal outcomes are similar to non-pregnant adults, and vertical transmission and neonatal infection are rare.” However, research notes that pregnant women must be taken into consideration when developing vaccines and therapeutic drugs for COVID-19.
Access to Healthcare
Some Canadians in urban settings, remote and isolated communities and First Nation, Inuit and Métis communities may face barriers in accessing healthcare services, especially during a pandemic. Individuals who rely on others for care at home or for transportation to healthcare services may face barriers in accessing care.
Accessing healthcare may also be of specific concern for individuals who are:
- living with physical or mental disabilities;
- limited in their ability to speak in English or French;
- seniors; and
- new immigrants or refugees.
The physical environment can also put individuals at risk of illness during a pandemic. For example, individuals who are homeless, or who live in overcrowded housing, or in prisons may be at particular risk of falling ill because of a limited ability to self-isolate or because of challenges in accessing water, sanitation and hygiene facilities.
Global evidence suggests that residents of care homes, most of whom are seniors, are particularly vulnerable to SARS-CoV-2 infection and dying from COVID-19. In Canada, residents and staff in long-term care (LTC) homes make up over 80% of the country’s COVID-19 deaths; preliminary research suggests that this rate is higher than that in comparable facilities in many other countries. The majority of residents and staff of LTC homes in Canada are women, which could be a contributing factor to higher COVID-19 death rates among women than men in Canada.
Better quality and higher levels of education correlate with higher levels of health literacy, which is an individual’s ability to understand and use information to make decisions that maintain and improve health. During a public health emergency such as a pandemic, high levels of health literacy among a population can lead to the quick adoption of behaviours to slow the spread of disease and can counter harmful misinformation.
Limited access to health information and relatively low levels of health literacy tend to be concentrated among some vulnerable populations in Canada.
Research on the messaging provided by public health agencies during the 2014 Ebola outbreak in West Africa suggests that the materials should be in plain language and be adaptable to different cultures, religions and languages.
Income, Employment and Working Conditions
During pandemics, authorities may recommend or order citizens to stay home except for essential activities. Without additional supports, individuals with lower incomes, fewer job benefits, or precarious work are less able to stay home despite illness or public health recommendations, putting their health – and those with whom they are in contact – at risk.
For example, individuals who rely on precarious or gig work as their sole source of income may not have access to Employment Insurance and may therefore be reluctant to stay at home because of the financial impact. The federal government has extended the Canada Emergency Response Benefit to certain workers, such as contract workers, who would not otherwise be eligible for Employment Insurance.
In addition, individuals working in positions deemed essential may be unable to work from home. As a result, certain groups of workers are at greater risk than others of falling ill or spreading disease during a pandemic, including:
- Workers in the healthcare sector (including doctors, nurses and long-term care workers) – a predominantly female workforce – are at greater risk of exposure to the virus than the rest of the population; and
- Certain retail workers (a predominantly female workforce) and police officers, truck and transit drivers, construction workers, miners (all sectors with a predominately male workforce), and other workers deemed essential, are not directly exposed to the virus but cannot work from the safety of their home.
Outside of paid employment, women perform more unpaid care than men, including tending to sick family members, which may put them at increased risk of contracting an illness from a sick family member.
*(all Canadian data from the Public Health Agency of Canada: see full epidemiological report)
Authors: Clare Annett, Robert Mason and Laura Munn-Rivard, Library of Parliament