Released in the Journal of SLEEP, an Australian research study has found that 41per cent of commercial truck drivers have obstructive sleep apnoea and of those 16 per cent are categorised as being severe.

 

Given that untreated obstructive sleep apnoea (OSA) roughly doubles the risk of crashing this study has serious road safety implications.

 

Of the 517 long distance commercial truck drivers who drove a vehicle greater than 12 tons tare weight, only 12 per cent reported wake time sleepiness using the Epworth Sleepiness Scale (ESS). The ESS relies on people self reporting their wake time sleepiness levels.

 

Ron Grunstein, Professor of Sleep Medicine, CIRUS, University of Sydney and co-author of the research said, “The aim of the study was to determine whether self reporting sleepiness levels were an accurate tool to identify OSA.

 

“The question of self reporting sleepiness levels is very important because Australian truck drivers are required to complete the ESS questionnaire as part of a medical examination to obtain a commercial motor vehicle licence.

 

Prof. Mark Stevenson, Director of the Monash University Accident Research Centre in Melbourne and study lead investigator said, “This study has important implications for licensing truck drivers as it shows that current licence requirements would not identify those with sleep disorders.

 

“These findings show there is a significant difference between self reporting and clinical testing for OSA and related sleepiness.

 

“We know there is an elevated risk of crashing in drivers with untreated OSA therefore it is important that truck drivers—behind the wheels of the largest vehicles on the road and at times with combustible freight—should be tested with a diagnostic tool that does not rely on self-reporting.”

 

The truck drivers reported working 65.4 hours per week on average and 40 per cent of the truck drivers admitted having trouble staying awake while driving at least once in the last month and 17 per cent reported experiencing this at least twice a week.

 

The truck drivers reported sleeping fewer hours on work days but on days off 38 per cent reported sleeping an extra two hours which is an indicator of chronic sleep loss.

 

Of the 517 truck drivers interviewed and tested 50 per cent were obese, 49.5% were smokers and 18 per cent had hypertension but only 13 per cent took medication to treat it.

 

Prof Grunstein added, “While the optimal method to screen for sleep apnea in commercial drivers has yet to be found, it is clear that some sort of testing is required, as reliance on self report alone is insufficient. Screening for sleep apnea and on-going treatment is required to reduce the risk of driving and performance impairment that may lead to a crash.”

 

The drivers involved in the study were long distance truck drivers (travelling at least 200 KM from their base), drove trucks greater than 12 tonnes tare weight such as semi-trailers, B-Doubles or road trains

 

Lisa Sharwood from The George Institute and lead author said, “Study participants were approached and recruited from 25 heavy vehicle truck stops across the road network in two states in Australia namely, New South Wales and Western Australia and is the largest study of its kind”.

 

The study involved researchers from the University of Sydney, Monash University Accident Research Centre, University of New South Wales, The George Institute for Global Health, Queensland University of Technology and Curtin University as well as support from the Australian Research Council.