UP STUDY - Decipher Persistent Critical Illness Through in Deep Clinical Phenotyping. (UPSt_UCI)

April 8, 2026 updated by: Susana Mendes Fernandes, Lisbon Academic Medical Center - Centro Académico de Medicina de Lisboa

Persistent Critical Illness (PCI) is a condition that affects some patients who remain in the Intensive Care Unit (ICU) for a long time, usually more than 10-14 days. It is estimated to occur in 5-20% of critically ill patients. A recent Portuguese study found that more than 14% of ICU patients stayed longer than 14 days. PCI is often associated with ongoing need for life support, such as mechanical ventilation or medications to maintain blood pressure. However, patients may also experience severe muscle weakness, repeated infections, or other complications, which makes this group very diverse.

One of the main risk factors for prolonged ICU stay is sepsis, a severe infection that affects the whole body. Other factors-such as prior health conditions, use of corticosteroids, sedation practices, early versus late mobilization, fluid and antibiotic management, and delirium treatment-may also influence the development and course of PCI.

This study aims to identify different clinical patterns ("clusters") among critically ill patients who remain in the ICU for more than 10 days. Patients will be followed until hospital discharge, and up to one year if data are available. Understanding these different patterns will help develop more personalized and effective care strategies for each patient profile.

The study is a multicenter retrospective cohort including adult patients (≥18 years) admitted to participating ICUs for more than 5 days between 2021 and 2023. Data collected will include demographic, clinical, and laboratory information, details of organ support (such as mechanical ventilation or vasopressors), medications, nutrition, and rehabilitation practices.

Statistical and machine learning methods will be used to identify groups of patients with similar clinical trajectories and to assess how these groups are related to outcomes such as survival, recovery of organ function, or long-term disability.

Expected results are the identification of distinct clinical clusters of PCI that combine clinical and laboratory data, and the development of tailored management strategies to improve recovery and outcomes for patients with PCI.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Portugal
    • Lisbon District
      • Lisbon, Lisbon District, Portugal
        • Recruiting
        • Centro Hospitalar de São João / ULS São João
        • Contact:
        • Principal Investigator:
          • José Artur Paiva, MD PhD
        • Sub-Investigator:
          • Cristiana Paulo, MD PhD
      • Lisbon, Lisbon District, Portugal
        • Recruiting
        • Hospital de Vila Franca de Xira / ULS Estuário do Tejo
        • Contact:
        • Principal Investigator:
          • João Gonçalves Pereira, MD PhD
        • Sub-Investigator:
          • André Oliveira, MD PhD
      • Lisbon, Lisbon District, Portugal
      • Lisbon, Lisbon District, Portugal
        • Recruiting
        • Hospital Garcia de Orta / ULS Almada-Seixal
        • Contact:
        • Principal Investigator:
          • Antero Fernandes, MD PhD
        • Sub-Investigator:
          • Rui Gomes, MD PhD
      • Lisbon, Lisbon District, Portugal
        • Recruiting
        • Hospital Prof. Doutor Fernando Fonseca / ULS Amadora -Sintra
        • Contact:
          • Paulo Teles Freitas, MD PhD
          • Phone Number: 351 214 348 200
          • Email: ptf@netcabo.pt
        • Principal Investigator:
          • Paulo Teles Freitas, MD PhD
        • Sub-Investigator:
          • Tiago Ramires, MD PhD
        • Sub-Investigator:
          • Cristiana Gonçalves, MD PhD
      • Lisbon, Lisbon District, Portugal
        • Recruiting
        • Hospital São Francisco Xavier / Centro Hospitalar de Lisboa Ocidental
        • Contact:
        • Principal Investigator:
          • Pedro Póvoa, MD PhD
        • Sub-Investigator:
          • João Frutuoso, MD PhD
    • Porto District
      • Vila Nova de Gaia, Porto District, Portugal
        • Not yet recruiting
        • Hospital de VIla Nova de Gaia-Espinho / ULS Gaia e Espinho
        • Contact:
        • Principal Investigator:
          • Rute Alves, MD PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This study will include adult patients (≥18 years old) who are consecutively admitted to participating intensive care units (ICUs) and remain in the ICU for 5 or more days. The focus will be on patients who survive the early phase of critical illness, allowing the formation of a relatively homogeneous cohort of early ICU survivors.

The population will comprise patients with a wide range of critical illnesses, including sepsis, respiratory failure, cardiovascular instability, and multi-organ dysfunction, who require ongoing organ support such as invasive mechanical ventilation or vasopressors. Patients with prolonged ICU stays exceeding 10 days who continue to require organ support will be further characterized as having Persistent Critical Illness.

Description

Inclusion Criteria:

  • Adult patients aged 18 years or older;
  • ICU length of stay equal to or greater than 5 days.

Exclusion Criteria:

  • Patients with an ICU stay < 5 days;
  • Patients discharged from the ICU early due to lack of ward availability, rather than clinical recovery;
  • Patients who do not survive the early phase of critical illness (i.e., early ICU deaths).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Adult patients (≥18 years) admitted to participating ICUs for more than 5 days.
Adult patients (≥18 years) admitted to participating intensive care units (ICUs) who remained in the ICU for more than 5 days.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Need for one or more continuous organ support treatment at Day 10
Time Frame: The first 10 days in the ICU
Data from patients who remain in the ICU for more than 10 days requiring ongoing organ support, such as invasive mechanical ventilation, renal replacement therapy or vasopressors, will be used to identify those who develop Persistent Critical Illness and to enable subsequent cluster analysis of their clinical trajectories.
The first 10 days in the ICU

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
All cause mortality stratified by Persistent Critical Illness (PCI) clusters
Time Frame: From cluster identification (Day 10) until hospital discharge or up to 1-year follow-up if available.

Clinical outcomes will be assessed and reported according to clusters of Persistent Critical Illness (PCI) identified using unsupervised machine learning analysis at Day 10 of ICU stay. Outcome includes:

• All-cause mortality, reported as the proportion of participants who die during hospitalization and up to 1 year after cluster identification.
From cluster identification (Day 10) until hospital discharge or up to 1-year follow-up if available.
Organ dysfunction stratified by Persistent Critical Illness
Time Frame: From cluster identification (Day 10) until hospital discharge or up to 1-year follow-up if available.

Clinical outcomes will be assessed and reported according to clusters of Persistent Critical Illness (PCI) identified using unsupervised machine learning analysis at Day 10 of ICU stay. Outcome includes:

• Organ dysfunction, assessed using the Sequential Organ Failure Assessment (SOFA) score, reported as mean (± SD) or median (IQR) values after cluster identification.
From cluster identification (Day 10) until hospital discharge or up to 1-year follow-up if available.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
ICU mortality
Time Frame: Through ICU stay (up to 1 year).
Death occurring at any time during the ICU stay.
Through ICU stay (up to 1 year).
Hospital mortality
Time Frame: Through hospital stay (up to 2 years).
Death occurring at any time during the hospital admission.
Through hospital stay (up to 2 years).
ICU length of stay
Time Frame: Through ICU stay (up to 1 year).
Total number of calendar days from ICU admission to ICU discharge.
Through ICU stay (up to 1 year).
Incidence of ICU-acquired infections
Time Frame: Through ICU stay (up to 1 year).
Number of clinically or microbiologically documented infections acquired ≥48 hours after ICU admission.
Through ICU stay (up to 1 year).
Hemoglobin trajectory
Time Frame: Through ICU stay (up to 1 year).
Longitudinal assessment of hemoglobin levels using repeated measurements obtained during the intensive care unit (ICU) stay.
Through ICU stay (up to 1 year).
C-reactive protein (CRP) trajectory
Time Frame: Through ICU stay (up to 1 year).
Longitudinal assessment of C-reactive protein levels using repeated measurements obtained during the intensive care unit stay.
Through ICU stay (up to 1 year).
Creatinine trajectory
Time Frame: Through ICU stay (up to 1 year).
Longitudinal assessment of creatinine levels using repeated measurements obtained during the intensive care unit stay.
Through ICU stay (up to 1 year).
Albumin trajectory
Time Frame: Through ICU stay (up to 1 year).
Longitudinal assessment of albumin levels using repeated measurements obtained during the intensive care unit stay.
Through ICU stay (up to 1 year).
Lactate trajectory
Time Frame: Through ICU stay (up to 1 year).
Longitudinal assessment of lactate levels using repeated measurements obtained during the intensive care unit stay.
Through ICU stay (up to 1 year).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Lisbon Academic Medical Center - Centro Académico de Medicina de Lisboa

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Centro Hospitalar de Vila Nova de Gaia/Espinho
Centro Hospitalar Lisboa Ocidental
Centro Hospitalar De São João, E.P.E.
Hospital Vila Franca de Xira
Unidade Local de Saúde Almada-Seixal
Hospital Prof. Doutor Fernando Fonseca

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Susana Fernandes, MD PhD, Lisbon School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 13, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 3, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 30, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 3, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • UP STUDY

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data collected in this study will be made available to other researchers. All data will undergo a thorough anonymization process prior to sharing to prevent direct or indirect identification of participants. Each patient will be assigned an internal numeric code, consisting of two digits representing the center of origin and four sequential digits assigned by order of admission. No personal identifiers (e.g., name, national ID number, full date of birth, address) are collected.

The anonymized dataset will be accompanied by a data dictionary, describing each variable and its format, to allow full interpretation and reuse of the data. This approach ensures participant confidentiality and complies with ethical and legal requirements, while enabling secondary analyses, replication studies, or meta-analyses by other researchers.

IPD Sharing Time Frame

The individual participant data and accompanying data dictionary will be made available after the completion of dat of interest for the study publication, starting December 1, 2028, and will remain accessible for years thereafter.

IPD Sharing Access Criteria

De-identified individual participant data and the corresponding data dictionary will be made available to qualified researchers whose proposed use of the data has been reviewed and approved by the study's coordinating center or ethics committee. Before sharing, all datasets will be verified, curated, and securely stored in accordance with applicable data protection regulations and current ethical and scientific recommendations.

Researchers will have access to fully anonymized datasets containing all study variables, excluding any directly or indirectly identifiable information. Data will be shared upon reasonable request through a secure, controlled-access repository, following submission of a research proposal and a data use agreement that ensures confidentiality and appropriate data use.

The anonymized dataset and related documentation will be deposited in a certified open research repository, such as Zenodo, Dryad, or Figshare, and will be assigned a Digital Object Identifier (DOI).

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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