The authors note that the difference in hospitalization rate may be partly due to existing immunity to influenza in the population.
In a recent study, investigators compared data between patients with the coronavirus disease 2019 (COVID-19) and patients with influenza who were admitted to hospitals over a 2-month period in spring 2020 and a 3-month period during the seasonal flu outbreak of 2018 and 2019. They discovered that nearly twice as many people were admitted to hospitals for COVID-19 in comparison to those admitted for the flu.
The study, published in the journal The Lancet Respiratory Medicine, gathered data supplied by the French national administrative database (Programme de Médicalisation des Systèmes d'Information, PMSI) to look at how COVID-19 admissions compared to influenza admissions at the peak of the pandemic and the previous year’s flu season. The database contains all patient details who were either admitted to public or private hospitals in France. This includes why the patients were admitted and what type of care they received during their stay.
The findings showed that 15,104 COVID-19 patients out of the study’s 89,530 died. This is in comparison to 2,640 flu patients dying, making COVID-19’s death rate almost 3 times higher. In addition to the higher death rate, a greater proportion of patients diagnosed with COVID-19 required time in intensive care units (14,585 vs. 4,926).
"Our study is the largest to date to compare the two diseases and confirms that COVID-19 is far more serious than the flu,” Catherine Quantin, a co-lead author on the study said. “The finding that the COVID-19 death rate was three times higher than for seasonal influenza is particularly striking when reminded that the 2018/2019 flu season had been the worst in the past five years in France in terms of number of deaths."
Other findings from the study demonstrated that patients with COVID-19 were 2 times as likely to require invasive mechanical ventilation (8,684 vs. 1,822) and that their average length of stay in the hospital was twice as long (15 days vs. 8 days). Acute respiratory failure also more heavily impacted COVID-19 patients, with more than 1 in 4 experiencing it.
Fewer children under the age of 18 were observed with COVID-19 compared to ones admitted for influenza (1,227 vs. 8,942). Patients in the age group of 11-17 years with COVID-19 had 10 times the death rate than those with influenza (14 of 361 vs 65 of 6,973), although the case fatality rate remained very low.
"Taken together, our findings clearly indicate that COVID-19 is much more serious than seasonal influenza,” Pascale Tubert-Bitter, co-lead author on the study said. “At a time when no treatment has been shown to be effective at preventing severe disease in COVID-19 patients, this study highlights the importance of all measures of physical prevention and underlines the importance of effective vaccines."