Pressure on the Health-Care System and Intensive Care Utilization During the COVID-19 Outbreak in the Lombardy Region of Italy: A Retrospective Observational Study in 43,538 Hospitalized Patients

  1. Filippo Trentini
  2. Valentina Marziano
  3. Giorgio Guzzetta
  4. Marcello Tirani
  5. Danilo Cereda
  6. Piero Poletti
  7. Raffaella Piccarreta
  8. Antonio Barone
  9. Giuseppe Preziosi
  10. Fabio Arduini
  11. Petra Giulia Della Valle
  12. Alberto Zanella
  13. Francesca Grosso
  14. Gabriele del Castillo
  15. Ambra Castrofino
  16. Giacomo Grasselli
  17. Alessia Melegaro
  18. Alessandra Piatti
  19. Aida Andreassi
  20. Maria Gramegna
  21. Marco Ajelli
  22. Stefano Merler

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Abstract

During the spring of 2020, the coronavirus disease 2019 (COVID-19) epidemic caused an unprecedented demand for intensive-care resources in the Lombardy region of Italy. Using data on 43,538 hospitalized patients admitted between February 21 and July 12, 2020, we evaluated variations in intensive care unit (ICU) admissions and mortality over the course of 3 periods: the early phase of the pandemic (February 21–March 13), the period of highest pressure on the health-care system (March 14–April 25, when numbers of COVID-19 patients exceeded prepandemic ICU bed capacity), and the declining phase (April 26–July 12). Compared with the early phase, patients aged 70 years or more were less often admitted to an ICU during the period of highest pressure on the health-care system (odds ratio (OR) = 0.47, 95% confidence interval (CI): 0.41, 0.54), with longer ICU delays (incidence rate ratio = 1.82, 95% CI: 1.52, 2.18) and lower chances of dying in the ICU (OR = 0.47, 95% CI: 0.34, 0.64). Patients under 56 years of age had more limited changes in the probability of (OR = 0.65, 95% CI: 0.56, 0.76) and delay to (incidence rate ratio = 1.16, 95% CI: 0.95, 1.42) ICU admission and increased mortality (OR = 1.43, 95% CI: 1.00, 2.07). In the declining phase, all quantities decreased for all age groups. These patterns may suggest that limited health-care resources during the peak phase of the epidemic in Lombardy forced a shift in ICU admission criteria to prioritize patients with higher chances of survival.

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  1. Version published to 10.1093/aje/kwab252
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    SciScore for 10.1101/2020.11.06.20149690: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIRB: The institutional ethics board of Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico in Milan approved this study and due to the nature of retrospective chart review, waived the need for informed consent from individual patients.
    Consent: The institutional ethics board of Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico in Milan approved this study and due to the nature of retrospective chart review, waived the need for informed consent from individual patients.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Stratum-specific odds ratio were computed using STATA.
    STATA
    suggested: (Stata, RRID:SCR_012763)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    This work has some limitations. First, we defined the period of healthcare strain solely on the basis of ICU bed occupancy, largely overlapped with the temporal evolution of the hospital bed occupancy (Figure S2). Further data to better characterize different aspects of hospital strain, such as the availability of ventilators, healthcare staff, drugs used for COVID-19 therapy and personal protective equipment, were not available. In addition, we did not have information about inter-hospital referrals which might provide further insight in the dynamics of healthcare strain for individual hospitals. The somewhat arbitrary threshold on the number of occupied ICU beds adopted for the definition of the three periods in our analysis may be a possible source of bias. This threshold was chosen on the basis of the pre-emergency ICU bed availability and in the attempt to obtain a good trade-off between balancing the number of hospitalized patients in the three periods and balancing the temporal duration of the periods. Second, we did not have more granular information on the individual therapeutic course and on the use of life support measures. According to a recent report, about 87% of ICU patients in Lombardy received invasive mechanical ventilation, while the remaining were assisted with non-invasive respiratory support [14]. Third, information on individual comorbidities was coarsely represented by three macro categories (cardiovascular, respiratory and metabolic) that contained di...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  3. Version published to 10.1101/2020.11.06.20149690v1 on medRxiv