By Stan Deresinski, MD
Clinical Professor of Medicine, Stanford University
SYNOPSIS: Among hospitalized patients requiring oxygen support at admission, COVID-19 was three times more fatal than was influenza.
SOURCE: López Montesinos I, Arrieta-Aldea I, Dicastillo A, et al; COVID-MAR Group. Comparison of hospitalized coronavirus disease 2019 and influenza patients requiring supplemental oxygen in a cohort study: Clinical impact and resource consumption. Clin Infect Dis 2022;75:2225-2238.
López Montesinos and colleagues in Barcelona retrospectively compared outcomes among patients admitted to the hospital with either influenza or COVID-19 who required supplemental oxygen therapy. The influenza cases (65% influenza A H1N1 and 26.7% influenza B) were admitted between 2017 and 2019, while those with COVID-19 were admitted during the first wave of the pandemic between March and May 2020. One hundred eighty-seven in each group were included in the analysis. The requirement of a need for oxygen therapy assured a somewhat similar severity of disease at the time of admission.
The cohorts were imbalanced, with COVID-19 patients being younger and having fewer comorbidities and being more likely to have radiographic evidence of pneumonia. Seventeen percent of influenza patients had been vaccinated against this infection; COVID-19 vaccines were not available during the period of study. Oseltamivir was administered to 98% of the influenza patients, while only 1% of COVID-19 patients received remdesivir (17% received lopinavir-ritonavir). The majority of COVID-19 patients did not receive corticosteroids.
Concomitant bacterial pneumonia was present on admission in a larger proportion of influenza patients, while hospital-acquired pneumonia was diagnosed more frequently in those with COVID-19 — an observation likely explained by their longer duration of hospitalization. This also likely accounted for the fact that non-pulmonary nosocomial infections also were more frequent in COVID-19 patients. Antibacterial agents were administered to 90.4% and 96.3% of influenza and COVID-19 patients, respectively — many more than were believed to have bacterial pneumonia.
COVID-19 patients were more likely to require respiratory support and were three times more likely to require intensive care, and they remained in intensive care for a longer time. In addition, COVID-19 was associated with significantly longer hospital stays, as well as both testing and pharmaceutical costs. Finally, patients with COVID-19 were approximately three times more likely to have died at 30 days (29/187; 15%) than those with influenza (10/187; 5%); hazard ratio, 3.07; 95% confidence interval, 1.5 to 6.31). The corresponding 90-day mortality rates were 19% and 6%. COVID-19 was an independent risk factor for mortality at both times.
COMMENTARY
Relatively early in the COVID-19 pandemic, a number of individuals argued, often on political rather than medical grounds, that COVID-19 was no worse than influenza. This study, performed before the availability of a COVID-19 vaccine and in the almost complete absence of effective anti-SARS-CoV-2 drugs, demonstrates the fallacy of this stance. COVID-19 was associated with greater cost, morbidity, and, most importantly, mortality when compared to influenza. These findings are similar to those previously reported in France that examined all hospitalized patients without regard to their requirement for supplemental oxygen on admission.1
Whether this conclusion is still valid in the current context remains to be seen. SARS-CoV-2 has changed, the majority of the population has some degree of immunity, and effective therapies now are available. The situation remains dynamic.
REFERENCE
- Piroth L, Cottenet J, Mariet AS, et al. Comparison of the characteristics, morbidity, and mortality of COVID-19 and seasonal influenza: A nationwide, population-based retrospective cohort study. Lancet Respir Med 2021;9:251-259.
