A large observational study examined population-wide data for 13 postacute conditions in patients who had been hospitalized with a COVID-19 infection and found that all but one of these conditions, venous thromboembolism, occurred at comparable rates in those hospitalized for sepsis and influenza.
“For us, the main takeaway was that patients hospitalized for severe illness in general really require ongoing treatment and support after they’re discharged. That type of care is often very challenging to coordinate for people in a sometimes siloed and fragmented health care system,” study author Kieran Quinn, MD, PhD, a clinician at Sinai Health in Toronto, and assistant professor at the University of Toronto, said in an interview.
The study was published in JAMA Internal Medicine.
Postacute effects
The investigators compared clinical and health administrative data from 26,499 Ontarians hospitalized with COVID-19 with data from three additional cohorts who had been hospitalized with influenza (17,516 patients) and sepsis. The sepsis cohort was divided into two groups, those hospitalized during the COVID-19 pandemic (52,878 patients) and a historical control population (282,473 patients).
These comparators allowed the researchers to compare COVID-19 with other severe infectious illnesses and control for any changes in health care delivery that may have occurred during the pandemic. The addition of sepsis cohorts was needed for the latter purpose, since influenza rates dropped significantly after the onset of the pandemic.
The study outcomes (including cardiovascular, neurological, and mental health conditions and rheumatoid arthritis) were selected based on previous associations with COVID-19 infections, as well as their availability in the data, according to Dr. Quinn. The investigators used diagnostic codes recorded in Ontario’s Institute for Clinical Evaluative Sciences database. The investigators observed some of the studied conditions in their own patients. “Many of us on the research team are practicing clinicians who care for people living with long COVID,” said Dr. Quinn.
Compared with cohorts with other serious infections, those hospitalized with COVID-19 were not at increased risk for selected cardiovascular or neurological disorders, rheumatoid arthritis, or mental health conditions within 1 year following hospitalization. Incident venous thromboembolic disease, however, was more common after hospitalization for COVID-19 than after hospitalization for influenza (adjusted hazard ratio, 1.77).
The study results corroborate previous findings that influenza and sepsis can have serious long-term health effects, such as heart failure, dementia, and depression, and found that the same was true for COVID-19 infections. For all three infections, patients at high risk require additional support after their initial discharge.
Defining long COVID
Although there was no increased risk with COVID-19 for most conditions, these results do not mean that the postacute effects of the infection, often called “long COVID,” are not significant, Dr. Quinn emphasized. The researcher believes that it’s important to listen to the many patients reporting symptoms and validate their experiences.
There needs to be greater consensus among the global health community on what constitutes long COVID. While the research led by Dr. Quinn focuses on postacute health conditions, some definitions of long COVID, such as that of the World Health Organization, refer only to ongoing symptoms of the original infection.
While there is now a diagnostic code for treating long COVID in Ontario, the data available to the researchers did not include information on some common symptoms of post-COVID condition, like chronic fatigue. In the data used, there was not an accurate way to identify patients who had developed conditions like myalgic encephalomyelitis/chronic fatigue syndrome and postural orthostatic tachycardia syndrome, said Dr. Quinn.
In addition to creating clear definitions and determining the best treatments, prevention is essential, said Dr. Quinn. Prior studies have shown that vaccination helps prevent ICU admission for COVID-19.