COVID-19NCT04462393
Characteristics and Outcomes of Patients Admitted to Swedish Intensive Care Units for COVID-19
An observational study of COVID-19 and Critical Illness, run by Linkoeping University at 1 site in Sweden.
Trial summary
This is a registry-based cohort study of all adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19, Critical Illness
- What is being tested?
- Admission to ICU for COVID-19
- How many people
- 7,500 participants
- Where
- 1 siteSweden
- Study dates
- 6 Mar 2020to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic (6 March-6May2020).
Who may be able to join
- Adult patients (≥18 years)
- COVID-19 disease
Who cannot join
- No Swedish personal identity number
- 'Opt out' from Swedish Intensive Care Registry
Trial locations and contacts
1 site in 1 country.
Sweden1 site
Department of Anaesthesia and Intensive Care, Linkoeping University Hospital, Region Östergötland
Linköping, Östergötland County, 50185
About this study
Official title: Characteristics and Outcomes of Patients Admitted to Swedish Intensive Care Units for COVID-19 During the First 60 Days of the 2020 Pandemic
This is a registry-based cohort study of all adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic.
The main goal is to describe demographic characteristics, coexisting conditions, treatments and outcomes among critically ill patients with COVID-19. A secondary goal is to identify independent risk factors associated with increased mortality for these patients.
Read more
Data regarding baseline characteristics including comorbidities, intensive care treatments and outcomes will be extracted. ICU lengths of stay and 30-day mortalities will be calculated. The primary outcome is 30-day all-cause mortality. THIS PART OF THE STUDY HAS BEEN COMPLETED.
UPDATE 26 Feb 2022:
Characteristics and outcomes of 'first wave' patients admitted to Swedish ICUs was published in Eur J Anaesthesiol. 2021 Apr 1;38(4):335-343. doi: 10.1097/EJA.0000000000001459.
A description of the surge response and aggregated data outcomes in Scandinavian countries was published in https://onlinelibrary.wiley.com/doi/10.1111/aas.13983.
UPDATE 13 Nov 2024:
ADDITIONAL SUMMARY - EXTENDED INCLUSION PERIOD AND ADDITION OF LONG-TERM OUTCOMES, AND CRITICALLY ILL PATIENTS WITH INFLUENZA AND VIRAL PNEUMONITIS Due to the continued influx of patients requiring intensive care due to COVID-19, we extended the inclusion period to 31 Dec 2022. Thus this new cohort will include all patients admitted to ICUs in Sweden from 6 March 2020 to 31 Dec 2022.
We will investigate short (30day mortality) and long-term outcomes (365d mortality and cardiovascular complications) of patients admitted to Swedish ICUs with confirmed SARS-CoV-2 infection and COVID-19 disease.
In international research, the long-term effects of ICU-requiring COVID-19 are now highly topical. Long-term follow-up exceeding one year has not yet been conducted on any Swedish material. To concretely understand the actual implications of long-term outcomes, it is becoming almost standard to compare this patient group to ICU-requiring influenza + viral pneumonitis patients to some extent. We have applied for and obtained ethical approval to include this group as a potential comparator to COVID-19 patients.
However, such comparisons require careful consideration of potential confounders, such as patient characteristics and socioeconomic factors.
It is therefore crucial to both establish the disease burden for the population and relate it to a comparable patient group. Ethical approval and national data linkage approvals have now been obtained to extract this data from Statistics Sweden and the Swedish National Board of Health and Welfare registries. Data linkage was completed in October 2024.
Read the detailed description
Previous studies reporting outcomes for COVID-19 patients admitted to intensive care units (ICUs) have been hampered by right-censoring after short observation periods. None have reported 30-day mortality rates and the vast majority of studies have substantial proportions of undischarged patients at the time of follow-up. The lack of follow-up at least to ICU discharge may cause bias in reported mortality rates. Further, national data on critically ill patients have not been previously published.
UPDATE 26 Feb 2022: A number of large, cohort studies including national population outcomes have now been published.
This is a registry-based cohort study of all adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic. The Swedish Intensive Care Registry (SIR) collects data on patients admitted to all Swedish ICUs, with 100% coverage since 2019. Thus, SIR is able to report on outcomes in a national intensive care population without selection. Little is known about the epidemiology of COVID-19 infections in Sweden, which has one of the world's highest life expectancies and a significant burden of comorbidity. Coupled with Sweden's 'relaxed' approach to COVID-19 pandemic management, health care outcomes are understandably under question.
The main goal is to describe demographic characteristics, coexisting conditions, treatments and outcomes among critically ill patients with COVID-19. A secondary goal is to identify independent risk factors associated with increased mortality for these patients.
ADDITIONAL SUMMARY updated 20 October 2021 Due to the continued influx of COVID-19 patients in ICUs in Sweden throughout 2020 and 2021, we extended of our sample size to encompass all patients admitted up to 30 June 2021 (previously 6 May 2020).
We aim to investigate short- and long-term outcomes including mortality and the incidence of new cardiovascular and respiratory diagnoses up to one year after inclusion.
On 22 mar 2021 we received ethical committee approval for these extensions.
UPDATE 31 October 2024 We have sought and obtained ethical approval to extend the inclusion period to 31 Dec 2022. Data linkage with the Swedish causes of death registry, Swedish Death Registry, Swedish National Patient Registry was approved and data obtained on 11 Oct 2024. This data will be used to investigate long-term outcomes including mortality, new cardiovascular and respiratory diagnoses. Compared to the update on 20 Oct 2021, we will investigate outcomes at longest follow-up, rather than at one year.
We have also sought and obtained ethical approval to expand the cohort to include all patients with viral pneumonitis admitted to Swedish ICUs between 1 jan 2005-31 dec 2022. This cohort will act as a comparator group to COVID-19 patients.
- Conditions
- COVID-19, Critical Illness
- Being tested
- Admission to ICU for COVID-19
- Medical subject headings
- COVID-19, Critical Illness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Admission to ICU for COVID-19Other
All patients admitted to Swedish ICUs with COVID-19 between 6 Mar - 6 May 2020
What is being measured
The primary outcome is the main question the study is designed to answer.
30-day mortality
all-cause
Measured: 30 days
365-day mortality
all-cause
Measured: 365 days (additional outcome added Oct 2021 after additional approval from ethical committee)
Secondary outcomes (2)
ICU mortality
all cause
Measured: 30 days
Morbidity
Cardiovascular and Respiratory Diseases
Measured: up to 365 days after study inclusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2020
- Study start6 Mar 2020
- Primary completion31 Oct 2024
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by Linkoeping UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 7,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Linkoeping University
- Sponsor type
- Other government
- Collaborators
- Region Östergötland
- Responsible party
- Principal investigator, Michelle Chew, Linkoeping University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04462393
- Sponsor's protocol ID
- SweCOVID
- Status last verified
- Mar 2026
- First submitted
- 6 Jul 2020
- Last updated
- 17 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Unidentified data will be shared conditional upon application to the CI
Publications
Chew MS, Blixt PJ, Ahman R, Engerstrom L, Andersson H, Berggren RK, Tegnell A, McIntyre S. National outcomes and characteristics of patients admitted to Swedish intensive care units for COVID-19: A registry-based cohort study. Eur J Anaesthesiol. 2021 Apr 1;38(4):335-343. doi: 10.1097/EJA.0000000000001459.
PubMed 33534266
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characteristics and Outcomes of Patients Admitted to Swedish Intensive Care Units for COVID-19 During the First 60 Days of the 2020 Pandemic
- ClinicalTrials.gov ID
- NCT04462393
- Acronym / sponsor ID
- SweCOVID
- Conditions
- COVID-19, Critical Illness
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 7,500 participants (estimated)
- Lead sponsor
- Linkoeping UniversityOther government
- Collaborators
- Region Östergötland
- Study start
- 6 Mar 2020 (actual)
- Primary completion
- 31 Oct 2024 (actual)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 8 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a registry-based cohort study of all adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic.
The main goal is to describe demographic characteristics, coexisting conditions, treatments and outcomes among critically ill patients with COVID-19. A secondary goal is to identify independent risk factors associated with increased mortality for these patients.
Data regarding baseline characteristics including comorbidities, intensive care treatments and outcomes will be extracted. ICU lengths of stay and 30-day mortalities will be calculated. The primary outcome is 30-day all-cause mortality. THIS PART OF THE STUDY HAS BEEN COMPLETED.
UPDATE 26 Feb 2022:
Characteristics and outcomes of 'first wave' patients admitted to Swedish ICUs was published in Eur J Anaesthesiol. 2021 Apr 1;38(4):335-343. doi: 10.1097/EJA.0000000000001459.
A description of the surge response and aggregated data outcomes in Scandinavian countries was published in https://onlinelibrary.wiley.com/doi/10.1111/aas.13983.
UPDATE 13 Nov 2024:
ADDITIONAL SUMMARY - EXTENDED INCLUSION PERIOD AND ADDITION OF LONG-TERM OUTCOMES, AND CRITICALLY ILL PATIENTS WITH INFLUENZA AND VIRAL PNEUMONITIS Due to the continued influx of patients requiring intensive care due to COVID-19, we extended the inclusion period to 31 Dec 2022. Thus this new cohort will include all patients admitted to ICUs in Sweden from 6 March 2020 to 31 Dec 2022.
We will investigate short (30day mortality) and long-term outcomes (365d mortality and cardiovascular complications) of patients admitted to Swedish ICUs with confirmed SARS-CoV-2 infection and COVID-19 disease.
In international research, the long-term effects of ICU-requiring COVID-19 are now highly topical. Long-term follow-up exceeding one year has not yet been conducted on any Swedish material. To concretely understand the actual implications of long-term outcomes, it is becoming almost standard to compare this patient group to ICU-requiring influenza + viral pneumonitis patients to some extent. We have applied for and obtained ethical approval to include this group as a potential comparator to COVID-19 patients.
However, such comparisons require careful consideration of potential confounders, such as patient characteristics and socioeconomic factors.
It is therefore crucial to both establish the disease burden for the population and relate it to a comparable patient group. Ethical approval and national data linkage approvals have now been obtained to extract this data from Statistics Sweden and the Swedish National Board of Health and Welfare registries. Data linkage was completed in October 2024.
Detailed description
Previous studies reporting outcomes for COVID-19 patients admitted to intensive care units (ICUs) have been hampered by right-censoring after short observation periods. None have reported 30-day mortality rates and the vast majority of studies have substantial proportions of undischarged patients at the time of follow-up. The lack of follow-up at least to ICU discharge may cause bias in reported mortality rates. Further, national data on critically ill patients have not been previously published.
UPDATE 26 Feb 2022: A number of large, cohort studies including national population outcomes have now been published.
This is a registry-based cohort study of all adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic. The Swedish Intensive Care Registry (SIR) collects data on patients admitted to all Swedish ICUs, with 100% coverage since 2019. Thus, SIR is able to report on outcomes in a national intensive care population without selection. Little is known about the epidemiology of COVID-19 infections in Sweden, which has one of the world's highest life expectancies and a significant burden of comorbidity. Coupled with Sweden's 'relaxed' approach to COVID-19 pandemic management, health care outcomes are understandably under question.
The main goal is to describe demographic characteristics, coexisting conditions, treatments and outcomes among critically ill patients with COVID-19. A secondary goal is to identify independent risk factors associated with increased mortality for these patients.
ADDITIONAL SUMMARY updated 20 October 2021 Due to the continued influx of COVID-19 patients in ICUs in Sweden throughout 2020 and 2021, we extended of our sample size to encompass all patients admitted up to 30 June 2021 (previously 6 May 2020).
We aim to investigate short- and long-term outcomes including mortality and the incidence of new cardiovascular and respiratory diagnoses up to one year after inclusion.
On 22 mar 2021 we received ethical committee approval for these extensions.
UPDATE 31 October 2024 We have sought and obtained ethical approval to extend the inclusion period to 31 Dec 2022. Data linkage with the Swedish causes of death registry, Swedish Death Registry, Swedish National Patient Registry was approved and data obtained on 11 Oct 2024. This data will be used to investigate long-term outcomes including mortality, new cardiovascular and respiratory diagnoses. Compared to the update on 20 Oct 2021, we will investigate outcomes at longest follow-up, rather than at one year.
We have also sought and obtained ethical approval to expand the cohort to include all patients with viral pneumonitis admitted to Swedish ICUs between 1 jan 2005-31 dec 2022. This cohort will act as a comparator group to COVID-19 patients.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients (≥18 years) admitted to Swedish Intensive Care Units with confirmed SARS-CoV-2 infection and COVID-19 disease during the first 2 months of the 2020 pandemic (6 March-6May2020).
Key inclusion criteria (2 listed)
- Adult patients (≥18 years)
- COVID-19 disease
Key exclusion criteria (2 listed)
- No Swedish personal identity number
- 'Opt out' from Swedish Intensive Care Registry
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Admission to ICU for COVID-19All patients admitted to Swedish ICUs with COVID-19 between 6 Mar - 6 May 2020 | Other | – |
Primary outcome
30-day mortality
Time frame: 30 days
all-cause
365-day mortality
Time frame: 365 days (additional outcome added Oct 2021 after additional approval from ethical committee)
all-cause
2 secondary outcomes
ICU mortality
Time frame: 30 days
Morbidity
Time frame: up to 365 days after study inclusion
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
- Derived from this study: PubMed 33534266Chew MS, Blixt PJ, Ahman R, Engerstrom L, Andersson H, Berggren RK, Tegnell A, McIntyre S. National outcomes and characteristics of patients admitted to Swedish intensive care units for COVID-19: A registry-based cohort study. Eur J Anaesthesiol. 2021 Apr 1;38(4):335-343. doi: 10.1097/EJA.0000000000001459.
- Individual participant dataSharing planned: Undecided. Unidentified data will be shared conditional upon application to the CI
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19 and Critical Illness, run by Linkoeping University at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
30-day mortality (time frame: 30 days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04462393, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026; AzTrials last refreshed its copy on 8 Nov 2026.