Comparison of Hospitalized Coronavirus Disease 2019 and Influenza Patients Requiring Supplemental Oxygen in a Cohort Study: Clinical Impact and Resource Consumption

Abstract

Background To compare clinical characteristics, outcomes, and resource consumption of patients with COVID-19 and seasonal influenza requiring supplemental oxygen. Methods Retrospective cohort study conducted at a tertiary-care hospital. Patients admitted due to seasonal influenza between 2017 and 2019, or with COVID-19 between March and May 2020 requiring supplemental oxygen were compared. Primary outcome: 30-day mortality. Secondary outcomes: 90-day mortality and hospitalization costs. Attempted sample size to detect an 11% difference in mortality was 187 patients per group. Results COVID-19 cases were younger (median years, 67 (IQR 54-78) vs 76 (IQR 64-83); p < 0.001) and more frequently overweight whereas influenza cases had more hypertension, immunosuppression, and chronic heart, respiratory and renal disease. Compared to influenza, COVID-19 cases had more pneumonia (98% vs 60%, <0.001), higher MEWS and CURB-65 scores and were more likely to show worse progression on the WHO ordinal scale (33% vs 4%; p < 0.001). The 30-day mortality rate was higher for COVID-19 than for influenza: 15% vs 5% (p = 0.001). The median age of non-surviving cases was 81 (IQR 74-88) and 77.5 (IQR 65-84) (p = 0.385), respectively. COVID-19 was independently associated with 30-day (HR 4.6, 95%CI, 2-10.4) and 90-day (HR 5.2, 95%CI, 2.4-11.4) mortality. Sensitivity and subgroup analyses, including a subgroup considering only patients with pneumonia, did not show different trends. Regarding resource consumption, COVID-19 patients had longer hospital stays and higher critical care, pharmacy, and complementary test costs. Conclusions Although influenza patients were older and had more comorbidities, COVID-19 cases requiring supplemental oxygen on admission had worse clinical and economic outcomes.

Single-Center Experience in Detecting Influenza Virus, RSV and SARS-CoV-2 at the Emergency Department

“…Despite numerous uncertainties, SARS-CoV-2, specifically the Omicron (B.1.1.529) variant, influenza virus and RSV, may have similarities in terms of symptoms, immune responses, laboratory parameters, the mean viral loads of affected individuals [ 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 ], the rate of asymptomatic infections and the protective effect of face masks [ 111 , 112 ], although the duration of viral shedding may be longest in SARS-CoV-2 infections [ 78 , 79 , 80 ].…”

Comparative Analysis of Clinical Outcomes Using Propensity Score Matching: Coronavirus Disease 2019 vs. Seasonal Influenza in Korea

“…Patients in the pre-omicron group were younger and had fewer comorbidities than those in the remaining groups, consistent with the results of studies conducted during the initial stages of the pandemic. 11 12 13 14 15 16 Conversely, the baseline characteristics were similar between the omicron and influenza groups, with almost half of the patients aged ≥ 70 years and a high prevalence of comorbidities. The age distribution and prevalence of comorbidities varied among patients with the omicron variant and those with previous COVID-19 variants.…”

“…Furthermore, these studies showed conflicting results, with some indicating a higher prevalence of dyspnea in COVID-19 or influenza and other demonstrating no significant differences. 15 25 26 A Korean study found that dyspnea affected 10.6% and 23.4% of patients with pneumonia caused by COVID-19 and influenza, respectively. However, the study only investigated dyspnea of New York Heart Association class 2 or higher.…”

“…However, such studies were conducted during the early stages of the pandemic when effective treatment strategies had not yet been developed, which limits the generalizability of the findings. 11 12 13 14 15 16 Therefore, an updated evaluation of this topic is required.…”

Reply letter to “Immunogenicity and safety of a quadrivalent high-dose inactivated influenza vaccine compared with a standard-dose quadrivalent influenza vaccine in healthy people aged 60 years or older: a randomized Phase III trial”

“…18 Almost, all public health restrictions have now been lifted and this could increase the likelihood of more respiratory virus co-infections during future winters, substantially straining the available healthcare resources. 19 , 20 Interestingly, it is reported that influenza vaccination may be associated with a reduced risk of SARS-CoV-2 infection. 21 These results lend support to the importance of continuing vaccinating against Covid-19 as well as against Influenza.…”