Comparison of the characteristics, morbidity and mortality of COVID-19 between first and second/third wave in a hospital setting in Lombardy: a retrospective cohort study

Abstract

Coronavirus disease 2019 (COVID-19) represents a major health problem in terms of deaths and long-term sequelae. We conducted a retrospective cohort study at Montichiari Hospital (Brescia, Italy) to better understand the determinants of outcome in two different COVID-19 outbreaks. A total of 634 unvaccinated patients admitted from local emergency room to the Internal Medicine ward with a confirmed diagnosis of SARS-CoV-2 infection and a moderate-to-severe COVID-19 were included in the study. A group of 260 consecutive patients during SARS-CoV-2 first wave (from February to May 2020) and 374 consecutive patients during SARS-CoV-2 2nd/3rd wave (from October 2020 to May 2021) were considered. Demographic data were not significantly different between waves, except a lower prevalence of female sex during first wave. Mortality was significantly higher during the 1st wave than in the following periods (24.2% vs. 11%; p < 0.001). Time from symptoms onset to hospital admission was longer during first wave (8 ± 6 vs. 6 ± 4 days; p < 0.001), while in-hospital staying was significantly shorter (10 ± 14 vs. 15 ± 11 days; p < 0.001). Other significant differences were a larger use of corticosteroids and low-molecular weight heparin as well less antibiotic prescription during the second wave. Respiratory, bio-humoral and X-ray scores were significantly poorer at the time of admission in first-wave patients. After a multivariate regression analysis, C-reactive protein and procalcitonin values, % fraction of inspired oxygen on admission to the Internal Medicine ward and length of hospital stay and duration of symptoms were the strongest predictors of outcome. Concomitant anti-hypertensive treatment (including ACE-inhibitors and angiotensin-receptor blockers) did not affect the outcome. In conclusion, our data suggest that earlier diagnosis, timely hospital admission and rational use of the therapeutic options reduced the systemic inflammatory response and were associated to a better outcome during the 2nd/3rd wave.

Long-Term Survival among Patients Hospitalized for COVID-19 during the First Three Epidemic Waves: An Observational Study in a Northern Italy Hospital

“…A literature search was carried out to retrieve other studies conducted in Italy, which, like us, carried out mortality analysis for COVID-19 patients admitted to hospital during the first three pandemic waves, both to compare our results with theirs and to understand whether other research groups conducted the follow-up of patients after discharge and for how long. In general, we found that the mortality trends that we observed among waves was very similar compared to that described by many other Italian research groups [ 6 , 7 , 8 , 23 , 25 , 27 , 28 , 29 ], with the highest mortality rate in hospitalized patients recorded during the first wave of the pandemic followed by a gradual decrease during the subsequent peaks of infection. Almost all studies involved patients who had been admitted to hospitals in Northern Italy.…”

“…Finally, one study did not perform any follow-up of patients after discharge, but it only considered death events that occurred during hospitalization by reporting an in-hospital mortality rate equal to 24% for the first wave, and 11% for the second/third [ 27 ].…”

Different death rates between COVID-19 waves among unvaccinated patients: moving beyond lessons learned

“…Leidi and colleagues in this issue of Internal and Emergency Medicine [ 1 ] confirm that COVID-19 waves are different in term of patients’ morbidity and mortality. In their paper, inpatient mortality was significantly higher (more than double) during the first wave than in the subsequent waves (24.2% vs. 11%).…”

Determinants of COVID-19-related mortality in an internal medicine setting

“…Three studies looking at COVID-19 in Lombardy in the first or second wave in an internal medicine setting have been published so far [ 14 – 16 ]. Overall, comparison among these studies is made difficult by the heterogeneous inclusion criteria and admission modalities, reflecting in different results, despite similar patient age ranges.…”

“…Overall, comparison among these studies is made difficult by the heterogeneous inclusion criteria and admission modalities, reflecting in different results, despite similar patient age ranges. For example, according to Bandera et al [ 15 ], the number of comorbidities and specific diseases (i.e., cancer, chronic heart failure, dementia and diabetes) were related to in-hospital mortality, while Leidi et al [ 14 ] did not find any association between survival and specific diseases. In the study by Ughi et al [ 16 ], the hazard ratio for mortality markedly increased with increasing Charlson comorbidity index.…”