Each year, approximately 30,000 children are unintentionally killed or injured while walking outside (typically within a half mile of their homes). Many factors—including children’s thinking and reasoning abilities, attention spans, reaction times, impulsiveness, and willingness to take risks—likely play a role. Excessive daytime sleepiness (EDS), whether from not getting enough sleep or a sleep disorder, negatively influences these factors. Therefore, researchers at the University of Alabama designed a laboratory-based test to measure the effect of EDS on the likelihood of children being involved in a motor vehicle-pedestrian crash.
Who were the participants and what did they do?
Thirty-three children with a diagnosis of hypersomnia of central origin (narcolepsy with or without cataplexy or idiopathic hypersomnia) and 33 healthy children (with normal scores on the Epworth Sleepiness Scale) took part in the study. Both groups were matched based on age, sex, race, and family income. The children with EDS did not take their wake-promoting medicine for three days before or on the morning of testing but continued to take medications for cataplexy. if they had cataplexy.
The experiments took place in a virtual-reality chamber that simulated standing at a curb with traffic coming from both directions and the sounds of cars and other typical traffic noise. When the children stood at the virtual curb and felt that it was safe to do so, they stepped off the curb and crossed the “street,” while their avatar matched their walking speed and crossed.
Who were the researchers and what did they do?
Dr. Kristin T. Avis and her coworkers hypothesized that children with EDS would have more hits or close calls than the matched group of healthy control children. They looked at the numbers of simulated injuries or near misses and compared the two groups. They also examined whether inattention to traffic or slowed decision making was related to being injured.
What were the results of the study?
The number of virtual hits or close calls in children with EDS was twice that of healthy children. Also, children with EDS had collisions or near-collisions on more than 10% of virtual street crossings and were more likely to be hit multiple times. The researchers also determined that the children had delayed decision-making abilities, not greater inattention. These study findings suggest that untreated EDS in children with central disorders of hypersomnolence may be associated with increased injury risk to children in pedestrian settings. The researchers also found that “children with EDS might take longer to determine the safety of crossing ambiguous traffic gaps than children without EDS. Longer delays in determining whether to cross could jeopardize children’s safety because they enter a safe traffic gap at a later time, thus creating a smaller traffic gap and less time before oncoming vehicles reach the crosswalk.”
Avis KT, Gamble KL, Schwebel DC. Does excessive daytime sleepiness affect children’s pedestrian safety? Sleep 2014;37:283-287.