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Risk Factors for Severe COVID-19 Disease

Current information suggests that older people and those with chronic health conditions are at higher risk of developing more severe illness or complications.

Last updated: May 18, 2021


Patients at higher risk for COVID-19 complications

  • Older people and those with chronic health conditions such as diabetes, heart disease and lung disease are at higher risk of developing more severe illness or complications from COVID-19. 
  • Most people with COVID-19 recover; however, people with chronic diseases are also at higher risk of death if they become ill. 
  • Learn more about chronic conditions, age and other socio-economic factors associated with more severe disease. A summary is also presented below.
  • Some individuals are considered clinically extremely vulnerable and have been prioritized for immunization. 

Risk Factors

Age is by far the single most important risk factor for severe illness or complications from COVID-19 including mortality. 

Age is by far the strongest predictor of hospitalization and mortality based on available data. The risk of severe illness and complications increases with age. Table 2 provides a breakdown of relative risk of mortality by age cohort using provincial data for the period of September 1, 2020 to January 5, 2021.



Read the full report on chronic conditions, age and other socio-economic factors associated with more severe disease.

The following risk factors are also associated with greater risk for severe illness: 

  • Asthma
  • Cancer
  • Cardiovascular 
  • Chronic Kidney Disease
  • Chronic Respiratory Disease
  • Diabetes 
  • Down Syndrome
  • Immunosuppression and Immunodeficiency
  • Obesity
  • Organ Transplant
  • Pregnancy
  • Sickle Cell Disease
  • Substance Use
Adults of any age with one or more underlying medical conditions or comorbidities are at increased risk for severe illness from COVID-19. Comorbidities associated with the greatest risk of severe illness, defined as having an adjusted risk ratio (aRR) above 2.5 based on provincial data and/or a mortality risk (hazard ratio) above 2.5 based on OpenSAFELY data, include those with chronic kidney disease with an eGFR < 30, down syndrome, and organ transplant. Other comorbidities associated with a greater risk of severe illness include cancer, cardiovascular disease, chronic respiratory disease, diabetes, gout, immunosuppression and immunodeficiency, obesity, pregnancy, and sickle cell disease. 

Table 1 summarizes the relative risk of severe illness associated with specific comorbidities identified in either epidemiological data from British Columbia and/or findings from published literature or other jurisdictions



Read the full report for more information on chronic conditions, age and other socio-economic factors associated with more severe disease.
  • Race, ethnicity, socio-economic factors and their intersection
  • Sex at birth
  • Other populations that warrant special consideration 
Read the full report on chronic conditions, age and other socio-economic factors associated with more severe disease..

Supporting patients

  • Get immunized with a COVID-19 vaccine when eligible.
  • Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer containing at least 60% alcoholand avoid touching their face. 
  • Wear a mask when outside of your home, especially indoors, and even outdoors if you are within 2 metres of someone else for more time than just passing by.
  • Stay 2 metres away from others
  • Avoid indoor crowded environments
  • Avoid large gatherings and stay away from other people who are ill. 
  • For more information on the spread and prevention of COVID-19, refer to the How It Spreads page.
 
  • It is prudent to have at least a two-week supply of medications on hand.
  • The Public Health Agency of Canada has issued guidance for all Canadians on preparedness and COVID-19.
  • The BC College of Pharmacists has information about visiting pharmacies and accessing medication.
  • It’s important to ensure patients continue to receive medical care for chronic conditions.
 
  • ‎People with certain chronic conditions (particularly people on medications that suppress the immune system) may consider “protective selfseparation.” This means staying separate from other people as much as possible. 
  • For many people, staying at home for long periods will not be an option. 
  • If there is widespread local transmission of COVID-19, people with chronic conditions should consider reducing their exposure to large gatherings, particularly those where they will be in close contact with others. 

SOURCE: Risk Factors for Severe COVID-19 Disease ( )
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