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Completed

NCT Number: NCT07089342

Exploring Biological Markers of Driver Fatigue for Enhanced Road Safety

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.

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Key information

Conditions

Drowsiness Fatigue Pathological Conditions, Signs and Symptoms Signs and Symptoms Sleepiness

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Vias institute

Brussels, Belgium

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • drivers randomly stopped by the police

Exclusion criteria

  • refusal to sign informed consent

Treatment and study plan

Primary outcomes

  1. 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.

Secondary outcomes

  1. Subjective sleepiness

    Time frame: Baseline: One time point after enrollment

    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).

  2. Behavioral markers of drowsy driving: Shivering

    Time frame: Baseline: One time point after enrollment

    Investigators will examine participants for behavioral abnormalities concerning shivering based on this scale: (i) yes (ii) no (iii) uncertain

  3. Behavioral markers of drowsy driving: Reaction

    Time frame: Baseline: One time point after enrollment

    Investigators will examine participants for behavioral abnormalities concerning reaction based on this scale: (i) slow/tired (ii) normal (iii) fast/talkative

  4. Behavioral markers of drowsy driving: Gait

    Time frame: Baseline: One time point after enrollment

    Investigators will examine participants for behavioral abnormalities concerning gait based on this scale: (i) slow (ii) normal (iii) uncertain

Sponsors and collaborators

Lead sponsor

University of Zurich

Other

Collaborators

  • Nationaal Instituut voor Criminalistiek en Criminologie Brussel
  • Vias Institute Brussel

Registry information

Acronym: FATIGUE

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jul 28, 2025
Registry last updated
Mar 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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