Study: Contributing causes, conditions and complications involved in COVID-19 deaths in Canada

Released: 2020-11-16

Existing research has provided evidence that people with pre-existing chronic conditions or compromised immune systems are at higher risk of dying of COVID-19, especially among those over the age of 80.

Statistics Canada is releasing a study today that confirms that the majority of Canadians who died of COVID-19 had at least one other cause, condition or complication (comorbidities) reported on the medical certificate of death.

Dementia or Alzheimer's disease are most closely associated with COVID-19 deaths

Of the over 9,500 COVID-involved deaths from March 1 to July 31, the majority (90%) had at least one other cause, condition or complication reported on the certificate.

Dementia or Alzheimer's was listed on the death certificate of 42% of the women and 33% of the men whose deaths involved COVID-19 up to July 31. Dementia or Alzheimer's is more prevalent among Canadians aged 85 and older, who represented more than half of COVID-19 deaths. Moreover, more than half of older long-term care (LTC) residents live with dementia. The Canadian Institute for Health Information has reported that during the first wave, LTC residents accounted for more than 80% of all COVID-19 deaths in the country.

Other common causes, conditions or complications listed on COVID-19 death certificates included pneumonia (33%), hypertensive diseases (15%), ischemic heart disease (13%), respiratory failure (13%), renal failure (12%) and diabetes (12%).

All these causes, conditions or complications are significantly more prevalent among Canadians aged 65 and older, who accounted for 94% of all COVID-19 deaths in the first wave. These causes, conditions or complications are also more prevalent among lower income Canadians, who may have been at increased risk of mortality from COVID-19 during the first wave of the pandemic.

The prevalence of specific COVID-19 comorbidities varies with age

The prevalence of specific COVID-19 comorbidities varied with age. For example, dementia or Alzheimer's were most often listed as a comorbidity among Canadians aged 65 years and older—especially among those aged 85 and older (listed on 46% of death certificates).

Pneumonia (44%) and respiratory failure (17%) were the most common comorbidities listed among COVID-involved deaths of Canadians aged 45 to 64 years old. Other common comorbidities in that age range included symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (15%), nervous system disorders excluding Alzheimer's, such as Parkinson's or ALS (15%), renal failure (14%) and diabetes (14%).

COVID-19 is also a contributing cause of death

Some deaths may have been related to COVID-19 but were ultimately attributable to another disease such as cancer, or an accidental injury such as a fall.

Nevertheless, COVID-19 was identified as the underlying cause of death in the vast majority (92%) of cases where COVID-19 was reported on the medical certificate (8,795 of the 9,525 deaths).

In the other 8% of cases (730 deaths), cancer (170 deaths), dementia or Alzheimer's (110 deaths), and other chronic conditions such as ischemic heart disease (105 deaths) or chronic lung disease (50 deaths) were most commonly found to be the underlying cause of death.

Products

The study "COVID-19 death comorbidities in Canada" is now available as part of the series StatCan COVID-19: Data to Insights for a Better Canada (Catalogue number45280001).

Contact information

For more information, or to enquire about the concepts, methods or data quality of this release, contact us (toll-free 1-800-263-1136; 514-283-8300; STATCAN.infostats-infostats.STATCAN@canada.ca) or Media Relations (613-951-4636; STATCAN.mediahotline-ligneinfomedias.STATCAN@canada.ca).