DrowsinessFATIGUENCT07089342
Exploring Biological Markers of Driver Fatigue for Enhanced Road Safety
An observational study of Drowsiness and Sleepiness, run by University of Zurich at 1 site in Belgium.
Trial summary
The aim of this study is to assess the effectiveness of biological markers in detecting fatigue/sleepiness in a sample of the general driving population in Belgium. The link between the collected biomarkers (oral fluid sample), observed signs of sleepiness in the driver and self-reported driver variables will be… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Drowsiness, Sleepiness, Fatigue
- How many people
- 511 participants
- Where
- 1 siteBelgium
- Study dates
- 29 Aug 2025to 19 Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
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
- Healthy volunteers accepted
- Adult, Older adult
Study population: Drivers (all vehicle types, aged 18 or older) voluntarily participating after being randomly stopped during roadside police checks in Belgium
Who may be able to join
- drivers randomly stopped by the police
Who cannot join
- refusal to sign informed consent
Trial locations and contacts
1 site in 1 country.
About this study
The aim of this study is to assess the effectiveness of biological markers in detecting fatigue/sleepiness in a sample of the general driving population in Belgium. The link between the collected biomarkers (oral fluid sample), observed signs of sleepiness in the driver and self-reported driver variables will be analysed. The analysis of the biological samples aims to measure endogenous metabolite levels that are possibly indicative for sleepiness of the donor driver. The respective metabolites will be chosen based on the results of a preceding clinical study (https://clinicaltrials.gov/study/NCT05585515). The objective of this study is to verify and validate the proposed metabolites as biomarkers for driver sleepiness in road traffic.
Read the detailed description
Researchers from NICC (National Institute of Criminalistics and Criminology) and VIAS will collect (1) saliva samples (Salivette with neutral swab allowing use by not-medically trained personnel; this sampling method is also used by the Belgian police in scope of the drugs in traffic legislation since 2019), (2) self-reported driver data (survey) and (3) observed driver data (form filled in by researchers) from drivers that were stopped on the road in scope of routine police checks. The collaboration with the police is because police can stop drivers randomly on-road while researchers cannot. After the police check, a researcher will ask if the driver wants to participate in a study on driver fatigue which is entirely independent from the police check. Voluntary drivers sign an informed consent form.
The collected saliva samples will be entirely separate from any sample obtained during the police checks. During data collection, the saliva sample, driver survey and observation form will each get a unique identification code to link the data. Afterwards, the researchers will work with this anonymised number and the data cannot be traced back to the participant.
All anonymised samples/data will temporarily be stored at NICC (Dept. Toxicology) and then be sent to the University of Zurich for analysis. The analysis of the saliva samples aims to measure endogenous metabolite levels that are possibly indicative for sleepiness of the donor. The correlation of the biomarker levels with observed/reported driver data will be measured. In specific cases the co-existence of drugs/medication in the saliva samples may also be tested: when the donor reported the consumption of the respective substance in the driver survey, as a confirmatory analysis, and (2) when the researchers believe the co-consumption of drugs/medication may interfere with the primary analysis. All anonymised samples will be stored at the University of Zurich for a maximum of 10 years and then be destroyed.
- Conditions
- Drowsiness, Sleepiness, Fatigue
- Keywords
- Fatigue, Drowsy driving, Sleepiness, Road Safety
- Medical subject headings
- Sleepiness, Fatigue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Road traffic population | People randomly stopped by police in public road traffic |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in metabolite concentrations in oral fluid quantified by liquid chromatography with mass spectrometry
Investigators will collect oral fluid samples for quantification of all detectable metabolites. Investigators will analyze which metabolite concentration values undergo significant changes with regard to sleep/wake history and demographical data of the donor.
Measured: Baseline: One collection time point after enrollment
Secondary outcomes (4)
Subjective sleepiness
Participants will complete the Karolinska Sleepiness Scale (version A) questionnaire. It is a 9-point scale, ranging from 1 (extremely alert) to 9 (very sleepy, great effort to keep awake, fighting sleep).
Measured: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Shivering
Investigators will examine participants for behavioral abnormalities concerning shivering based on this scale: (i) yes (ii) no (iii) uncertain
Measured: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Reaction
Investigators will examine participants for behavioral abnormalities concerning reaction based on this scale: (i) slow/tired (ii) normal (iii) fast/talkative
Measured: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Gait
Investigators will examine participants for behavioral abnormalities concerning gait based on this scale: (i) slow (ii) normal (iii) uncertain
Measured: Baseline: One time point after enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2025
- Study start29 Aug 2025
- Primary completion19 Dec 2025
- Study completion19 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DrowsinessStudies of the same condition, open and under way.
- More trials run by University of ZurichThe 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
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 511 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- Vias Institute Brussel, Nationaal Instituut voor Criminalistiek en Criminologie Brussel
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07089342
- Sponsor's protocol ID
- EC-2025-141
- Other IDs
- EC-2025-141
- Acronym
- FATIGUE
- Status last verified
- Mar 2026
- First submitted
- 9 Jul 2025
- Last updated
- 25 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Results will be published in peer-reviewed journals. Anonymized raw data will be made available upon request.
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exploring Biological Markers of Driver Fatigue for Enhanced Road Safety
- ClinicalTrials.gov ID
- NCT07089342
- Acronym / sponsor ID
- FATIGUE / EC-2025-141
- Conditions
- Drowsiness, Sleepiness, Fatigue
- Keywords
- Fatigue, Drowsy driving, Sleepiness, Road Safety
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 511 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Collaborators
- Vias Institute Brussel, Nationaal Instituut voor Criminalistiek en Criminologie Brussel
- Study start
- 29 Aug 2025 (actual)
- Primary completion
- 19 Dec 2025 (actual)
- Study completion
- 19 Dec 2025 (actual)
- First posted
- 28 Jul 2025 (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.
The aim of this study is to assess the effectiveness of biological markers in detecting fatigue/sleepiness in a sample of the general driving population in Belgium. The link between the collected biomarkers (oral fluid sample), observed signs of sleepiness in the driver and self-reported driver variables will be analysed. The analysis of the biological samples aims to measure endogenous metabolite levels that are possibly indicative for sleepiness of the donor driver. The respective metabolites will be chosen based on the results of a preceding clinical study (https://clinicaltrials.gov/study/NCT05585515). The objective of this study is to verify and validate the proposed metabolites as biomarkers for driver sleepiness in road traffic.
Detailed description
Researchers from NICC (National Institute of Criminalistics and Criminology) and VIAS will collect (1) saliva samples (Salivette with neutral swab allowing use by not-medically trained personnel; this sampling method is also used by the Belgian police in scope of the drugs in traffic legislation since 2019), (2) self-reported driver data (survey) and (3) observed driver data (form filled in by researchers) from drivers that were stopped on the road in scope of routine police checks. The collaboration with the police is because police can stop drivers randomly on-road while researchers cannot. After the police check, a researcher will ask if the driver wants to participate in a study on driver fatigue which is entirely independent from the police check. Voluntary drivers sign an informed consent form.
The collected saliva samples will be entirely separate from any sample obtained during the police checks. During data collection, the saliva sample, driver survey and observation form will each get a unique identification code to link the data. Afterwards, the researchers will work with this anonymised number and the data cannot be traced back to the participant.
All anonymised samples/data will temporarily be stored at NICC (Dept. Toxicology) and then be sent to the University of Zurich for analysis. The analysis of the saliva samples aims to measure endogenous metabolite levels that are possibly indicative for sleepiness of the donor. The correlation of the biomarker levels with observed/reported driver data will be measured. In specific cases the co-existence of drugs/medication in the saliva samples may also be tested: when the donor reported the consumption of the respective substance in the driver survey, as a confirmatory analysis, and (2) when the researchers believe the co-consumption of drugs/medication may interfere with the primary analysis. All anonymised samples will be stored at the University of Zurich for a maximum of 10 years and then be destroyed.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Road traffic population | – | –People randomly stopped by police in public road traffic |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Drivers (all vehicle types, aged 18 or older) voluntarily participating after being randomly stopped during roadside police checks in Belgium
Key inclusion criteria (1 listed)
- drivers randomly stopped by the police
Key exclusion criteria (1 listed)
- refusal to sign informed consent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Changes in metabolite concentrations in oral fluid quantified by liquid chromatography with mass spectrometry
Time frame: Baseline: One collection time point after enrollment
Investigators will collect oral fluid samples for quantification of all detectable metabolites. Investigators will analyze which metabolite concentration values undergo significant changes with regard to sleep/wake history and demographical data of the donor.
4 secondary outcomes
Subjective sleepiness
Time frame: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Shivering
Time frame: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Reaction
Time frame: Baseline: One time point after enrollment
Behavioral markers of drowsy driving: Gait
Time frame: Baseline: One time point after enrollment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2026.
- Individual participant dataSharing planned: Undecided. Results will be published in peer-reviewed journals. Anonymized raw data will be made available upon request.
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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 Drowsiness and Sleepiness, run by University of Zurich at 1 site in Belgium.
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 1 inclusion and 1 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: finished, as of the sponsor's last update on 25 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 Belgium. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Changes in metabolite concentrations in oral fluid quantified by liquid chromatography with mass spectrometry (time frame: Baseline: One collection time point after enrollment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 25 Mar 2026.