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U of T researchers lead effort to understand short- and long-term effects of COVID-19 on patients, caregivers

The Canadian COVID-19 Prospective Cohort study, led by U of T researchers, looks at how genomics, demographics, social factors and other variables influence disease progression and severity (photo by Marko Geber/Getty Images)

Many people who contract COVID-19 get better on their own at home, but more serious cases can involve hospitalization and months of recovery – or more. 

Angela Cheung and Margaret Herridge, both professors in the University of Toronto's department of medicine in the Temerty Faculty of Medicine, are co-leading an interdisciplinary team of more than 100 researchers who are studying short- and long-term outcomes for COVID-19 patients. The Canadian COVID-19 Prospective Cohort study (CanCOV) looks at how genomics, demographics, social factors and other variables influence disease progression and severity.

Angela Cheung
Angela Cheung (photo by Jessica Chang)

Several factors influence COVID-19 patient recovery, including age, general health and pre-existing medical conditions. Ventilation, sedative drugs and other interventions in the intensive care unit may be crucial and life-saving, but can also have consequences. 

“​The majority of patients who require mechanical ventilation for a week or more are unable to walk at the time of their ICU discharge, and it may take them months or up to one year or longer to recover,” says Herridge, a professor in the department of medicine and the Institute of Medical Science in the Temerty Faculty of Medicine.

Critically ill patients may ​require mechanical ventilation weeks or months, which may lead to lung injury and compromise respiratory muscles. Rapid muscle breakdown and immobility may further aggravate muscle loss and cause profound weakness.

These changes can result in functional dependency and compromise a person’s ability to carry out regular daily activities or return to work. “Many patients are left with life-long functional disability, cognitive and mood disorders,” says Herridge, who is also a senior scientist​ at Toronto General Hospital Research Institute (TGHRI)  and a respiratory and critical care physician at University Health Network.

For the study, CanCOV researchers planned to recruit 2,000 patients and 500 family caregivers from the four hardest hit provinces: Quebec, Ontario, Alberta and B.C. The research team includes experts in respiratory medicine, physical medicine and rehabilitation, critical care, occupational therapy, genetics and basic sciences. 

“We see patients and caregivers as a dyad. How people recover from illness is often tied to how they’re cared for,” says Cheung, who is also the KY and Betty Ho Chair of Integrative Medicine, and is a senior scientist at TGHRI and the Schroeder Arthritis Institute.

Margaret Herridge and Jill Cameron

“And we’ve learned from other conditions, ​including acute respiratory distress syndrome and SARS, ​that caregivers ​may acquire new mood disorders including anxiety, depression and post-traumatic stress disorder,” Cheung says.

In the first 14 months of the pandemic, there were more than 42,000 hospital stays averaging two weeks each for people with a COVID-19 diagnosis, according to the Canadian Institute for Health Information. Of that group, roughly 8,400 were admitted to intensive care. 

A recent publication by the Ontario Science Table suggests as many as 78,000 people in this province may have had or currently live with “long COVID,” a condition that can include fatigue, joint pain, brain fog, muscle and chest pain, and shortness of breath.

Kelly O'Brien, a physiotherapist and U of T associate professor in the department of physical therapy and the Rehabilitation Sciences Institute, sees parallels between long COVID and her previous work on disability related to HIV/AIDS. 

Kelly O'Brien

O’Brien recently co-authored a commentary in BMJ Global Health on conceptualizing long COVID as an episodic condition.

“Health-related challenges or symptoms experienced by adults living with long COVID can overlap, relapse, remit and change over time,” says O'Brien, who holds a Canada Research Chair in Episodic Disability and Rehabilitation. “These characteristics resemble episodic disability, a concept derived from the context of HIV, where health challenges are multidimensional in nature affecting physical, cognitive, mental and social health domains.”

Those challenges can fluctuate – sometimes unpredictably – daily or over longer periods of time, O’Brien says.
 
She is also part of a team working on a Canadian Institutes of Health Research-funded study, which will establish a patient-reported outcome measure to capture the nature and extent of episodic disability in people living with long COVID. The work will help guide access to rehabilitation, evaluate interventions and inform workplace policies.

In addition to her research, O’Brien is a member of Long COVID Physio, an international patient-led association of physiotherapists who live with long COVID and allies, which collaborated with World Physiotherapy to develop a briefing paper on rehabilitation approaches, including physical activity.

Jill Cameron, an associate professor in the department of occupational science and occupational therapy, studies caregiving and its impact on family members who assume this critical role.

She says the impact of COVID-19 on caregivers will prove to be intense, based what she and her colleagues have learned in the context of other conditions like dementia and stroke.

“Caregivers have to do more with less support,” says Cameron, who is also involved in the CanCOV study. “Throughout the pandemic, friends and family members haven’t been as able to come help as they might have prior to COVID.”

Professional services that would typically provide home visits have been limited, Cameron notes. “Public health measures have reduced the number of visits, and factors like cleaning protocols result in longer turnaround time between visits, which means workers can’t see the same caseloads,” Cameron says.

Early data from other studies and jurisdictions show increased caregiver stress and poorer mental health outcomes during the pandemic, as well as more restrictions on caregivers’ other work, leisure activities and care for other family members.

These impacts on caregivers are also likely to affect the well-being of COVID-19 patients. Research into these consequences is an emerging field, Cameron says, but she notes that, in the context of stroke, there is a connection between caregiver depression and patients who are more likely to be hospitalized in the year following their stroke.

Cameron says she is pleased to be contributing to research that may shed light on the impact of the ongoing pandemic.

“We’re doing great things, and we’re learning a lot here,” she says.

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