Patients hospitalized for either virus had an increased risk of death, hospital readmission, and health problems in multiple organ systems over 18 months of follow-up.
Rates of long-term health risks for patients hospitalized with COVID-19 or seasonal influenza are higher than was previously understood, according to research published in the Lancet Infectious Diseases.1 Investigators say the findings demonstrate the need for greater prevention of hospital admission for the 2 viruses.
COVID-19 and the flu are both known to be associated with a higher risk of death and negative health outcomes. Although previous studies have compared patients admitted to the hospital with the 2 viruses, the research generally focused on a small set of health outcomes within 6 months following an infection.
Investigators from the Washington University School of Medicine in St. Louis conducted a cohort study to complete a comparative evaluation of acute and long-term risks and burdens of a comprehensive set of health outcomes following hospital admission for COVID-19 or the flu.
“The idea that COVID-19 or flu are just acute illnesses overlooks their larger long-term effects on human health,” Ziyad Al-Aly, a co-author on the study and an assistant professor of medicine at Washington University, said in a release.2 “Before the pandemic, we tended to belittle most viral infections by regarding them as somewhat inconsequential: ‘You’ll get sick and get over it in a few days.’ But we’re discovering that is not everyone’s experience.”
Data for the study was collected from health-care databases of the US Department of Veteran Affairs. The study cohort included data from 81280 patients who were admitted to hospital for COVID-19 between March 2020 and June 2022. Data on 10985 patients admitted to hospital for seasonal influenza between October 2015 and February 2019 was also collected.
The study participants were followed for up to 18 months to evaluate risks and burdens of death, 94 individual health outcomes, 10 organ systems, overall burden across all organ systems, readmission, and admission to intensive care. The COVID-19 patients were further separated into 3 groups to differentiate between eras of the pandemic: pre-delta, delta, and omicron.
Investigators found that patients hospitalized for either virus had an increased risk of death, hospital readmission, and health problems in multiple organ systems over the 18 months of follow-up. Compared to the flu, patients with COVID-19 had an increased risk of death and an increased risk of 64 out of 94 pre-specified health outcomes. The flu had an increased risk of 6 out of 94 health outcomes.
COVID-19 had a higher risk across all organ systems, except for the pulmonary system, which was higher in the flu. Additionally, there was a higher burden of health loss in the post-acute phase compared to the acute phase for both viruses.
“Our findings highlight the continued need to reduce the risk of hospitalization for these two viruses as a way to alleviate the overall burden of health loss in populations,” Al-Aly said.2 “For both COVID-19 and seasonal influenza, vaccinations can help prevent severe disease and reduce the risk of hospitalizations and death. Optimizing vaccination uptake must remain a priority for governments and health systems everywhere.”