Insights from comparison of the clinical presentation and outcomes of patients hospitalized with COVID-19 in an Italian internal medicine ward during first and third wave

Abstract

BackgroundThe reasons of variability of clinical presentation of coronavirus disease-19 (COVID-19) across different pandemic waves are not fully understood, and may include individual risk profile, SARS-CoV-2 lineage and seasonal variations of viral spread. The objective of this retrospective study was to compare the characteristics and outcomes of patients admitted with confirmed coronavirus disease-19 (COVID-19) in the same season during the first (March 2020) and the third pandemic wave (March 2021, dominance of SARS-CoV-2 B.1.1.7 lineage) in an internal medicine ward of a large teaching hospital in Italy.Materials and methodsData of 769 unvaccinated patients (399 from the first and 370 from the third wave) were collected from clinical records, including symptom type and duration, extension of lung abnormalities on chest computed tomography (CT) and PaO2/FiO2 ratio on admission arterial blood gas analysis.ResultsThird wave patients were in average younger (median 65, interquartile range [IQR] 55–75, vs. 72, IQR 61–81 years old, p < 0.001), with less comorbidities and better pulmonary (CT visual score median 25, IQR 15–40, vs. 30, IQR 15–50, age- and sex-adjusted p = 0.017) and respiratory involvement (PaO2/FiO2 median 288, IQR 237–338, vs. 233, IQR 121–326 mmHg, age- and sex-adjusted p < 0.001) than first wave patients. Hospital mortality was lower (19% vs. 36%, p < 0.001), but not for subjects over 75 years old (46 vs. 49%). Age, number of chronic illnesses, PCT levels, CT visual score [Odds Ratio (OR) 1.022, 95% confidence interval (CI) 1.009–1.036, p < 0.001] and PaO2/FiO2 (OR 0.991, 95% CI 0.988–0.994, p < 0.001), but not the pandemic wave, were associated with mortality on stepwise multivariate logistic regression analysis.ConclusionDespite the higher virulence of B.1.1.7 lineage, we detected milder clinical presentation and improved mortality in patients hospitalized during the third COVID-19 wave, with involvement of younger subjects. The reasons of this discrepancy are unclear, but could involve the population effect of vaccination campaigns, that were being conducted primarily in older frail subjects during the third wave.

Evolution of in-hospital patient characteristics and predictors of death in the COVID-19 pandemic across four waves: are they moving targets with implications for patient care?

“…Several studies analyzed clinical characteristics and outcomes of patients admitted due to COVID-19 across the first three waves in Italy. These studies included mainly unvaccinated individuals showing an improvement in mortality, which paralleled a decrease in the median age ( 2 – 4 , 6 , 8 , 10 ). Similar data were found elsewhere in Europe ( 11 – 13 ).…”

“…According to the Italian National Surveillance System, since the beginning of the COVID-19 pandemic until April 2022, more than 26 million cases of SARS-CoV-2 infection were diagnosed (1). In Italy, the pandemic spread from the northern regions throughout all the Country, but a huge heterogeneity in incidence and fatality rates were reported since the first wave of the pandemic (2)(3)(4)(5)(6)(7)(8), evolving towards a lower number of cases and reduced severity of COVID-19. However, since SARS-CoV-2 infections continue to be reported and a recrudescence of the pandemic could occur, it is important to look back to the evolution of the pandemic to get lessons to better manage our patients.…”