A study that investigated the prevalence of sleepiness while driving has revealed that daytime sleepiness was fairly common among young Omani drivers. Various characteristics were found to be associated with daytime sleepiness while driving, including gender, BMI category, nocturnal sleep deprivation and snoring. This cross-sectional study took place at the Sultan Qaboos University Hospital, between May and July 2014. A total of 492 private vehicle drivers took part in the study of which 50.4% were male. Overall, 124 Omanis (25.2%) reported experiencing daytime sleepiness while driving at least once per month. The findings of this study, carried out by Dr. Mohammed Al Abri from the Department of Clinical Physiology at SQU Hospital and fellow researchers from SQU and the Hospital, were reported in SQU Medical Journal May 2018 issue.
Sleepiness and fatigue can decrease mental alertness and increase the likelihood of errors and unintentional injuries among children, adolescents and adults. In particular, fatigue and daytime sleepiness have been shown to impair cognitive function while driving, which results in a higher risk of road traffic crashes. Extended work shifts can also disrupt the sleep-wake cycle and therefore heighten the risk of occupational injuries and motor vehicle crashes. Nocturnal sleep deprivation and poor sleep hygiene are well-known causes of daytime sleepiness and tiredness, particularly among younger individuals. In addition to lack of sleep, there is evidence to suggest that sleep disorders such as obstructive sleep apnoea (OSA) can trigger excessive daytime sleepiness.
In the study, male drivers reported significantly greater daytime sleepiness compared to females (33.5% versus 18%). However, no gender difference was noted in terms of average nocturnal sleep duration. There was a significant association between daytime sleepiness while driving and nocturnal sleep deprivation, BMI and snoring. Among those who reported sleepiness while driving, the majority had fewer than 6 hours of sleep per night (69.3%) and were overweight (59.1%). Furthermore, the proportion of those with daytime sleepiness was doubled among those who snored compared to those who did not snore (36.2% versus 16.4%).
Car crashes are one of the most common causes of mortality and morbidity among young people in Oman, a country of approximately 4.5 million individuals. Sleepiness while driving is a leading cause of car crashes. The findings of the study indicated that sleepiness while driving was fairly common among private car drivers in Oman, with just over one quarter of the drivers reporting that they experienced daytime sleepiness while driving at least once a month. A significantly greater proportion of male drivers experienced daytime sleepiness while driving compared to females. Therefore, young males were found to carry a higher risk of daytime sleepiness while driving compared to females, despite the latter having a greater propensity towards daytime sleepiness in general. Multiple factors were observed to contribute to daytime sleepiness among drivers in the study.
Almost two-thirds of the sample had an inadequate nocturnal sleep duration of fewer than 6 hours per night, with a significant association between nocturnal sleep deprivation and daytime sleepiness while driving. A previous study found that 57.6% of Omani adolescents had fewer than 7 hours of sleep per night. This lack of sleep could be due to social- or work-related reasons, particularly in a society wherein most social events take place late at night.
Almost half of the participants in the present study had an Epworth Sleepiness Scale (ESS) score of fewer than 10, indicative of a greater propensity towards daytime sleepiness. There was also a significant association between sleepiness while driving and ESS score. These findings suggest that this scale could potentially be used as a screening tool to assess daytime sleepiness among driving license aspirants. The paper also reported an OSA prevalence of 10.6%, with a significant association between OSA and sleepiness while driving.
In a commentary on sleepy drivers, written in the same issue of SQU Medical Journal, Dr. Nabil Al Lawati from the Department of Medicine, Royal Hospital, Muscat, underscored the need for similar studies confirming the actual magnitude of the problem of sleepy driving in Oman using objective tools. “In the study conducted by Dr. Mohammed Al Abri and colleagues, data were subjectively collected using self-reported tools; it is therefore likely that the obtained results underestimate the true magnitude of the problem”, Dr. Nabil observed.
According to Dr. Nabil, the medical community should initiate nationwide campaigns advocating healthy sleep habits and raising public awareness of the numerous risks associated with sleep deprivation, both at the individual as well as societal levels. “It is high time that sleep medicine professionals join hands with law enforcement authorities and non-governmental organizations in Oman to create a common platform and work on preventing and dealing with the critical health-related and socioeconomic consequences of sleep deprivation, especially on the roads”, he noted.