An observational study in Long COVID, Long COVID-19 Syndrome and Long Covid19, sponsored by Rutger Lalieu. Active, not recruiting at 6 sites in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-06-04.
Sponsored by Rutger Lalieu · Observational
Post-Covid syndrome, also known as long Covid, is a clinical condition in which patients experience long term symptoms after Covid-19 infection. Treatment options for post-Covid are not effective. Therefore, there is an urgent need for a novel therapy. The first study results of HBOT in post-Covid patients are promising. Previous research from Israel has shown improvements in quality of life after HBOT. However, long term results are unknown. Therefore, this study aims to evaluate quality of life at one year after hyperbaric oxygen therapy in post-Covid patients with cognitive symptoms. It is hypothesized that quality of life at one year after HBOT is improved. Furthermore, this study aims to evaluate return to work after HBOT. To our knowledge this was not done before. An observational prospective cohort study will be conducted to answer the research questions. All post-Covid patients who are treated with hyperbaric oxygen therapy in participating centers, will be eligible for inclusion. Questionnaires and medical doctor consultations will be used in order to collect all data.
There are no risks for participants, since only 7 questionnaires are not part of standard clinical care. The burden is approximately 40 minutes extra in total for participants, compared to standard clinical care.
The study design is a prospective observational cohort study. Questionnaires and medical doctor consultations will be used in order to collect all data. All patients treated with HBOT have medical doctor consultations at baseline and every 10th session of HBOT (standard clinical care).
At baseline, the following characteristics will be collected: gender, age, BMI, medical history, Covid infection information, vaccination status, work status before Covid infection, previous Covid treatments, hospital and/or intensive care unit admission during Covid infection and smoking status. Furthermore, all patients treated are asked to fill out the SF-36 and EQ-5D questionnaires, a proprietary post-Covid symptoms questionnaire, and a questionnaire regaring work status. These questionnaires are repeated after 20, 40 (50) sessions of HBOT and after 3 and 12 months after the last treatment session.
During the following medical doctor consultations, side effects, changes in medication and interruptions of HBOT will be recorded as well to monitor compliance.
An interim analysis will be performed after 6 months to continue or stop treatments, based on the clinical results (as measured with the Physical Component Score of the SF-36 questionnaire). The minimal clinically important difference (MCID) to warrant early termination of therapy is if \<5% of patients improves 3 points. The upper limit (and reason to continue) is if >50% achieve an MCID of 7 points.
7,638 studies on the registry are indexed under COVID-19; 488 are open to participants now.
This study's planned enrollment of 200 is below the median of 260 across 3,135 observational studies indexed under COVID-19.
Browse COVID-19 studies →This is the only study on the registry with Rutger Lalieu as lead sponsor.
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The population will consist of post-Covid patients from the Netherlands, who are treated with hyperbaric oxygen therapy at several different treatment centers. All patients are adults and will receive standard clinical hyperbaric oxygen therapy at these clinics.
Exclusion Criteria:
All post-COVID patients that are referred for hyperbaric oxygen (and that are eligible for treatment)
Other: Hyperbaric oxygen therapy
HBOT per local protocol, i.e. 40 sessions 2.4 ATA, at the discretion of the hyperbaric physician
Quality of life 3 and 12 months
Is the expected improvement in quality of life in Long COVID patients after treatment with HBOT maintained at 12-months follow-up
Time frame: 3 and 12 months
Long Covid symptoms
What symptoms do Long COVID patients who were referred for HBOT suffer from?
Time frame: 3 and 12 months
Cognitive complaints
Is there any improvement of symptoms in Long COVID patients with cognitive symptoms during HBOT and after HBOT?
Time frame: 3 and 12 months
Work
Do changes in absence at work occur after treatment with HBOT in Long COVID patients with cognitive symptoms?
Time frame: 3 and 12 months
Risk factors quality of life
What are risk factors for low health related quality of life in Long COVID patients with cognitive symptoms who are treated with HBOT?
Time frame: 3 and 12 months
Profile of non-responders versus responders
What are the differences in baseline characteristics of patients that are non-responders and responders after HBOT?
Time frame: 3 and 12 months
Plan to share: No — The data is retrieved from patient files (after informed consent). Even though the data is pseudonymised, there is too much risk of confidentialty breach.
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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