130+
Indications for which HBOT has historically been explored.
A study designed for decades of learning
HORuS2050
A Multicentre Prospective Cohort and Biobank Study of Hyperbaric Oxygen Therapy Outcomes
1Nubiss GmbH, Berlin, Germany · 2Karolinska Institutet, Department of Physiology and Pharmacology, Stockholm, Sweden
A multicentre longitudinal cohort study building a continuous real-world evidence base for Hyperbaric Oxygen Therapy—beyond 2050.
Longitudinal study
- Baseline Medical history and participant-reported outcomes, recorded before treatment.
- Usual care Treatment decisions stay entirely with the treating centre.
- Follow-up The same outcome measures, repeated over time.
- 2050 and beyond No predefined end date—the cohort keeps growing.
Multicentre
Observational
Non-interventional
Prospective + retrospective
01 · Why HORUS2050?
Turning fragmented experience into shared evidence
HBOT is of broad clinical interest, but evidence remains dispersed across small studies, different treatment protocols and isolated patient groups.
10–15
Indications widely accepted by international hyperbaric medicine societies.
Growing
Use by self-paying patients and healthy individuals is rarely followed.
Why the evidence remains fragmented
Small, underpowered cohortsMostly single centre—even accepted indications lack large trials.
Limited research capacityMost HBOT facilities are private, with little incentive or funding; public centres lack the funding and resources to study at scale.
No unified outcome measuresDifferent questionnaires, follow-up windows and protocols make data difficult to pool.
Clinical recommendations also differ between European and national organisations, while polarised public discussion has contributed to scepticism across medical fields.
02 · Overall aim
Describe, compare and learn
HORUS2050 will create a standardised multicentre evidence base describing who receives HBOT and why, the chambers and protocols used, changes in participant-reported outcomes, benefits, limitations and potential harms, differences between cohorts and controls, and hypotheses for future interventional studies.
Understand utilisation
Describe diagnoses, symptoms, indications and health objectives treated at participating centres.
Observe outcomes
Follow participant-reported outcomes before and after HBOT and during longer-term follow-up.
Compare cohorts
Study relevant participant groups, protocols and untreated or propensity-matched controls.
Support future research
Generate hypotheses and inform the design and funding of future interventional studies.
Capture adverse reactions
HBOT is generally considered safe when delivered for accepted indications at centres following international recommendations. Collecting adverse reactions directly from participants safeguards against under-reporting.
Large datasets and routine-care biomarkers may later support exploratory predictive modelling. No predictive model is used for current clinical decision-making.
03 · Research framework
Study objectives
The registry begins by describing real-world HBOT practice, then compares outcomes across cohorts and explores questions that can shape future research.
- Describe the diagnoses, symptoms, indications and health objectives treated at participating HBOT centres.
- Analyse longitudinal changes in participant-reported outcome measures before and after HBOT and across follow-up periods.
- Record participant-reported adverse reactions, so that safety is captured directly from participants rather than under-reported.
- Describe chambers, pressures, gas mixtures and protocols.
- Describe staff qualifications and experience.
- Investigate how participants learn about HBOT and make decisions.
- Compare expected and reported outcomes.
- Compare relevant clinical cohorts and control groups.
- Explore routine-care biomarkers and associations with outcomes.
- Compare treated populations with matched control cohorts.
- Assess short-, medium- and long-term outcomes.
- Estimate national and European utilisation.
- Inform future predictive and interventional research.
04 · Study design
A longitudinal observational cohort
Multicentre, prospective, longitudinal and observational—with the possibility of retrospective data capture.
5
Countries expected
Q4 2026
First participant
100–300
Participants in year one
2050+
Long-term study horizon
Study pathway: participants enter at baseline or through retrospective data capture, and treatment stays entirely within usual clinical care.
ParticipantsPatients · Healthy participants · Controls
BaselineMedical data + PROMs
Usual careNo study intervention
Follow-upPROMs + outcomes
AnalysisLongitudinal cohort analysis
| Design | Multicentre observational cohort |
|---|---|
| Data direction | Prospective, with retrospective data capture where relevant |
| Clinical intervention | None |
| Population | Patients, healthy participants and comparator participants |
| Follow-up | Short, medium and long term |
| Sample size | Exploratory; no formal sample-size calculation |
| Duration | Multi-year, without a predefined end date and intended to continue beyond 2050 |
Patients treated before their centre joined the registry can still contribute where this is appropriate and permitted.
Previously treated participants
Retrospective data capture
Relevant cohort analysis
No study procedure influences clinical decision-making, treatment selection, pressure, gas mixture, dosing, timing or standard of care. Research data only.
05 · Participation
Who may contribute?
Inclusion: all individuals accepted for HBOT at a participating centre — at any pressure, gas mix or indication — who provide informed consent. Healthy volunteers are also eligible, forming a propensity-matched reference cohort.
Patients receiving HBOT
Accepted by a participating centre for any locally accepted condition, indication or objective.
The treating centre—not the study—decides whether HBOT is offered.
Healthy participants
Receiving HBOT for preventive-health, performance or another locally accepted objective.
Comparator participants
Selected individuals without HBOT exposure for control cohorts and matched analyses.
Previously treated participants may contribute through retrospective data entry where appropriate.
Exclusion: inability to comply with study procedures or informed consent (e.g. cognitive impairment or language barriers).
Final eligibility and consent requirements are determined by the participating centre and applicable national requirements.
06 · Data collection
Five streams, one dataset
Data contributing to the registry depend on the participant, indication, participating centre, consent and local standard of care.
Unified longitudinal research dataset
Questionnaire selection depends on the indication and applicable local standard of care.
| Instrument | Possible application |
|---|---|
| EQ-5D-5L | General health and quality of life |
| Fatigue Severity Scale | Chronic fatigue, including Long COVID cohorts |
| EORTC QLQ-C30 | Cancer-related quality of life |
| EORTC short forms | Indication-appropriate cancer and palliative-care outcomes |
| EPIC-26 | Prostate cancer-related outcomes |
| LENT-SOMA | Late normal-tissue effects |
07 · Planned analysis
Continuous evidence generation beyond 2050
Because HORUS2050 is exploratory, no formal sample-size calculation has been performed.
Approximately 100–300 participants are estimated during the first year, with enrolment expected to increase as more centres participate.
Analyses may be performed annually, at predefined enrolment milestones or on another rolling basis.
Relevant analyses may examine indication-specific cohorts, treatment protocols, participating centres and untreated or propensity-matched controls.
Future predictive modelling remains exploratory. HORUS2050 does not currently provide individual predictions or treatment recommendations.
Q4 2026
Expected first participant
Year one
Estimated 100–300 participants
Multicentre growth
Rolling analyses
Long-term follow-up
New cohorts and hypotheses
2050+
Continuous evidence generation
08 · Data governance
Research data, not clinical advice
HORUS2050 provides infrastructure for standardised research data handling. It does not replace clinical judgement.
The infrastructure supports
- Standardised data capture
- Longitudinal follow-up
- Comparable cohort structures
- Governed research analysis
It does not provide
- Diagnostic results
- Individual risk scores
- Treatment recommendations
- Clinical decision support
Information retained beyond the initial analytical phase will be held within a governed, pseudonymised research framework in accordance with applicable national and European requirements.
Where an appropriate local agreement exists, anonymised information may be transferred to the international HBOT eCRF in REDCap.
Biomarker results may be recorded where samples were obtained through local standard care. Biomarker collection is not an additional procedure required by HORUS2050.
Wearable data may contribute where applicable, technically supported and covered by the participant information and consent process.
Research use only
All HORUS2050 registry outputs are intended for research use only and are not intended to guide an individual participant’s clinical care.
09 · Multicentre participation
For HBOT centres and researchers
Comparable data from multiple centres can create larger, more diverse cohorts while retaining information about local practice.
- Centres expected at launch
- Potential centres
- Expanding towards the USA and India
- Use defined variables across centres and time points.
- Capture protocols and participant-reported outcomes in comparable structures.
- Support indication-specific and cross-cohort analyses.
- Generate hypotheses for future studies.
- Contribute to a long-term international research community.
- Collect through the Nubiss eCRF, purpose-built and maintained by the study.
Nubiss platform
Participant-reported outcomes, treatment data and physician-curated records are captured directly, in a record clinicians also use in care.
Approved local registry
A centre may keep another approved registry, provided the required variables can be mapped and extracted in a comparable structure.
REDCap eCRF
Where an appropriate agreement is in place, anonymised information may be transferred to the international HBOT eCRF held in REDCap.
Centre participation requires appropriate local review, governance agreements, data mapping, an approved participant-information process and documented separation between research collection and clinical decisions.
Contact the study team
A few short questions route your enquiry to the right person.
10 · Questions and answers
Frequently asked questions
Clear answers about participation, treatment independence, data collection and study duration.
No. HBOT is provided through usual clinical care. HORUS2050 records relevant information and outcomes but does not provide or prescribe treatment.
No. The study does not influence treatment selection, chamber, pressure, gas mixture, dose, timing or standard of care.
Healthy individuals may participate if accepted for HBOT by a participating centre for an objective accepted by that centre and if applicable consent requirements are met.
Yes. Relevant information may be entered retrospectively where appropriate, permitted and covered by the applicable governance process.
Not necessarily. Wearable data may be included where applicable, supported and covered by the participant information and consent process.
No additional biomarker sampling is required as a HORUS2050 study procedure. Results may be recorded only when samples were obtained through local routine care.
No. The infrastructure does not generate diagnostic results, individual risk scores, therapeutic recommendations or clinical decision support.
HORUS2050 is conceived as a multi-year longitudinal study without a predefined end date, with a research horizon extending beyond 2050.
Centre participation requires local review, governance agreements, data mapping and a suitable technical connection. Verified contact details and the formal process will be published before enrolment.
Yes. Selected patients and healthy individuals who have not received HBOT may contribute to comparator cohorts and propensity-matched analyses, subject to the applicable consent and governance requirements.
Before launch
Required publication details
First enrolment is expected in Q4 2026. The following verified information must be added before public recruitment.
- Participating centres
- Principal investigator and study-team contact details
- Protocol number, version and date
- Ethics committee and approval reference
- Approved participant information and consent documents
- ECHM consensus reference for the accepted HBOT indications
- Complete references supporting the scientific background
- Final privacy notice and jurisdiction-specific governance details