New Delhi: Ever wondered if the one driving your vehicle is well-rested or wished for a method to avert accidental sleeping while driving? Scientists have developed a new blood test that can accurately detect sleep-deprived drivers by using biomarkers that may help avoid road accidents in the future. The experts at Monash University in Australia, and the University of Birmingham, UK, noted that the level of sleep deprivation increases the risk of serious injury or fatality in critical situations.

The study, published in the journal Science Advances, shows that the biomarker used in the test accurately predicted when the study volunteers had been awake for over 24 hours under controlled laboratory conditions. Future work could examine whether these biomarkers are evident in saliva or breath and lead to a roadside test. The test detected whether individuals had been awake for 24 hours with a 99.2 percent probability of being correct when compared to well-rested samples, the researchers said.

When a single sample was considered without the well-rested comparison (similar to a diagnostic blood test), it dropped to 89.1 percent, which was still very high, they said. With about 20 percent of road accidents worldwide caused by sleep deprivation, researchers hope the discovery may inform future tests to quickly and simply identify sleep-deprived drivers. The biomarker could also be developed for other situations where sleep deprivation may lead to catastrophic consequences, such as in safety-critical workplaces.

This is a really exciting discovery for sleep scientists, and could be transformative to the future management of health and safety relating to insufficient sleep, said study senior author Clare Anderson who led the research while she was with Monash University. While more work is required, this is a promising first step, said Anderson, Professor at the University of Birmingham.

The researchers noted that there is strong evidence that less than five hours of sleep is associated with unsafe driving. However, driving after being awake for 24 hours is at least comparable to more than double the Australian legal limit of alcohol performance-wise, they said. The test may be also ideal for future forensic use but further validation is required. Study first author Katy Jeppe, from Monash University, said it was difficult to say how soon the test could be developed for post-accident use.

The next steps would be to test it in a less controlled environment and maybe under forensic conditions, particularly if it was to be used as evidence for crashes involving drivers falling asleep, Jeppe said. Given it is blood, the test is more limited in a roadside context, but future work could examine whether our metabolites and therefore the biomarker, are evident in saliva or breath, the researcher said. This sleep deprivation biomarker is based on 24 hours or more awake but can detect down to 18 hours awake. A biomarker for limited sleep over the previous night could be developed but more research is required to combine the time since sleep with the amount of sleep in the predictions.

"Much further work would be needed if laws were to change and a sleep deprivation test introduced on the road or in workplaces, Jeppe said. This would include further validation of biomarkers, as well as establishing safe levels of sleep to prevent and recover from impairment, not to mention the extensive legal process, he added.  

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