National outcomes and characteristics of patients admitted to Swedish intensive care units for COVID-19

  1. Michelle S. Chew
  2. Patrik Johansson Blixt
  3. Rasmus Åhman
  4. Lars Engerström
  5. Henrik Andersson
  6. Ritva Kiiski Berggren
  7. Anders Tegnell
  8. Sarah McIntyre

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Abstract

Mortality among patients admitted to intensive care units (ICUs) with COVID-19 is unclear due to variable follow-up periods. Few nationwide data are available to compare risk factors, treatment and outcomes of COVID-19 patients after ICU admission.

OBJECTIVE

To evaluate baseline characteristics, treatments and 30-day outcomes of patients admitted to Swedish ICUs with COVID-19.

DESIGN

Registry-based cohort study with prospective data collection.

SETTING

Admissions to Swedish ICUs from 6 March to 6 May 2020 with laboratory confirmed COVID-19 disease.

PARTICIPANTS

Adult patients admitted to Swedish ICUs.

EXPOSURES

Baseline characteristics, intensive care treatments and organ failures.

MAIN OUTCOMES AND MEASURES

The primary outcome was 30-day all-cause mortality. A multivariable model was used to determine the independent association between potential predictor variables and death.

RESULTS

We identified 1563 patients with complete 30-day follow-up. The 30-day all-cause mortality was 26.7%. Median age was 61 [52 to 69], Simplified Acute Physiology Score III (SAPS III) was 53 [46 to 59] and 62.5% had at least one comorbidity. Median P a O 2 /FiO 2 on admission was 97.5 [75.0 to 140.6] mmHg, 74.7% suffered from moderate-to-severe acute respiratory failure. Age, male sex [adjusted odds ratio (aOR) 1.5 (1.1 to 2.2)], SAPS III score [aOR 1.3 (1.2 to 1.4)], severe respiratory failure [aOR 3.0 (2.0 to 4.7)], specific COVID-19 pharmacotherapy [aOR 1.4 (1.0 to 1.9)] and continuous renal replacement therapy [aOR 2.1 (1.5 to 3.0)] were associated with increased mortality. Except for chronic lung disease, the presence of comorbidities was not independently associated with mortality.

CONCLUSIONS

Thirty-day mortality rate in COVID-19 patients admitted to Swedish ICUs is generally lower than previously reported despite a severe degree of hypoxaemia on admission. Mortality was driven by age, baseline disease severity, the presence and degree of organ failure, rather than pre-existing comorbidities.

TRIAL REGISTRATION NO

NCT04462393

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  1. ScreenIT

    SciScore for 10.1101/2020.08.06.20169599: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementConsent: Written, informed consent was not required.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.

    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:
    Limitations of this study include its retrospective nature, although data was prospectively registered in a large centralized database. We were unable to explore outcomes related to ethnicity or socioeconomic status as these are not registered in SIR. Specific data on laboratory variables such as lymphocyte counts and inflammatory parameters, ventilatory modes, sedation and analgesia and imaging were not recorded. Complications related COVID-19 are reported by each unit but are not validated and the degree of missing data varies widely from 100% for delirium and myocardial injury to 61% for acute kidney injury. Important complications such as venous thromboembolism, cardiac injury and cognitive dysfunction at discharge are not systematically queried and are likely to be substantially underreported in the SIRI database. While we make observations regarding pharmacological treatment and availability of ICU beds, any relationship with outcomes are purely speculative. Finally, we only capture data for the first two months of ICU admission and reported outcomes may change over the course of time; and may not be generalizable outside Sweden. The strengths of this study are that it encompassed an unselected population in Sweden, and captured the peak of COVID-19 admissions to intensive care units. This is significant in so far as it covers the period during which the intensive care capacity was maximally stressed, with possible consequences of outcome. We noted a significantly highe...

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04462393CompletedCharacteristics and Outcomes of Patients Admitted to Swedish…

    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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  2. Version published to 10.1097/eja.0000000000001459
  3. Version published to 10.1101/2020.08.06.20169599v1 on medRxiv