A Spanish study conducted during the first pandemic wave finds that adults hospitalized with COVID-19 were three times more likely to die within 30 days and 90 days than those hospitalized with seasonal influenza
Adults (18 years and older) hospitalized with COVID-19 have a higher risk of complications and death than those with the flu, despite being younger and having fewer chronic diseases, according to a retrospective cohort study conducted at the Hospital del Sea of Barcelona.
The findings, presented at this year’s European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Lisbon, Portugal, also suggest that COVID-19 is associated with longer hospital and intensive care stays, and costs almost double what needs to be treated.
For the study, researchers examined the medical records of 187 patients (average age 76 years, 55% men) admitted to the hospital with seasonal influenza infection between 2017 and 2019, and 187 patients with COVID-19 (average age 67 years, 49% men) hospitalized during the first wave of the pandemic between March and May 2020, who required oxygen therapy upon admission.
In both cohorts, patients were enrolled consecutively until the required sample size was reached. The study compared clinical characteristics, healthcare resource use outcomes (including length of stay, intensive care admission), hospital costs, and death.
Patients with influenza tended to have more existing chronic diseases and problems performing activities of daily living than patients with COVID-19, but were less likely to be overweight or obese (BMI of 25 kg/m² or more).
The analysis found that COVID-19 was associated with an increased risk of infection severity and ICU admission (26 [14%] influenza vs. 69 [39%] for COVID-19; see table in notes for editors).
Additionally, COVID-19 patients were more likely to experience certain complications, such as acute kidney injury, blood clots, and moderate to severe acute respiratory distress syndrome (where the lungs are unable to provide enough oxygen to the body’s vital organs). ; while patients with influenza were more likely to suffer from bacterial pneumonia (see table in notes to editors/abstract).
Overall, 29/187 (15%) COVID-19 patients and 10/187 (5%) influenza patients died from any cause within 30 days of hospitalization, and the mortality rate after 90 days was even higher (19%; 35/187 vs. 6%; 12/187). The authors note that there were no differences in mortality trends between the three seasonal influenza periods studied.
After accounting for potential confounders such as age, comorbidities, sex, disease severity, presence of pneumonia, and corticosteroid treatment, the researchers found that COVID-19 patients had more than three times more likely to die within 30 and 90 days of being admitted to the hospital than flu patients.
Additional analyzes showed that COVID-19 patients spent significantly more time in the hospital (mean [median] 14 days vs. 11 days) and ICU (17 vs. 10 days) compared to influenza patients. Furthermore, the average cost of critical care for COVID-19 patients was almost double that for flu patients (€21,350 vs. €12,082). Pharmacy treatment and testing costs were also significantly higher in the COVID-19 group.
“Our findings suggest that COVID-19 is much more lethal than influenza,” says lead author Dr. Inmaculada López Montesinos, of Hospital del Mar in Barcelona, Spain. “Even though influenza patients are older and have more comorbid illnesses, COVID-19 patients had consistently worse health outcomes and were considerably more expensive to treat. Even those people who are lucky enough to survive COVID-19 and leave the hospital will be forever marked by the consequences. “It is vital that people are fully vaccinated and boosted against both viruses.”
The authors acknowledge several limitations of their study, including that it was conducted in a tertiary care hospital in Spain, so the findings may not be generalizable to other populations. They also note that no genotyping studies were performed and although it is very likely that COVID-19 patients were affected by wild-type B.1, the results may not reflect the current scenario in which multiple SARS-CoV-2 variants. globally. Likewise, the absence of vaccinated COVID-19 patients during the study period may not reflect the current profile of hospitalized patients with COVID-19.
