By IANS,
London : Teens slept more and better at night after classes were rescheduled to commence 30 minutes later than usual timings, which also minimised their chances of auto-accidents.
Their sleep averaged from 12 minutes (grade nine) to 30 minutes (grade 12). The percentage who got at least eight hours of sleep per weeknight increased significantly from 35.7 percent to 50 percent.
Students who got at least nine hours of sleep also increased from 6.3 percent to 10.8 percent. The average amount of additional weekend sleep, or “catch-up sleep”, decreased from 1.9 hours to 1.1 hours.
Daytime sleepiness decreased, students using the Epworth Sleepiness Scale reported. Average crash rates for teen drivers in the study county in the two years after the change in timings dropped 16.5 percent, compared to the two years prior to the change, while teen crash rates for the rest of the state increased 7.8 percent over the same time period.
“It is surprising that high schools continue to set their start times early, which impairs learning, attendance and driving safety of the students,” said co-author Barbara Phillips, director of the UK Healthcare Good Samaritan Sleep Centre in Lexington, Ky.
A survey concerning the sleep habits of students from an entire county-wide school district in Kansas was distributed before and after a change in school start times, said a Good Samaritan release.
In April 1998, (year-I), a total of 9,966 students (66 percent of the total population of middle and high-school students enrolled in the county) from grades six to 12 completed questionnaires concerning their sleep habits on school nights and non-school nights and various aspects of daytime functioning.
In April 1999, (year-II), 10,656 students (72.8 percent of the total population of middle and high-school students enrolled in the county) filled out the same questionnaire.
School times during year-I were 7:30 a.m. for high schools and 8 a.m. for middle schools. In year-II high schools and middle schools started one hour later at 8:30 a.m. and 9 a.m.
These findings were published in the Monday issue of the Journal of Clinical Sleep Medicine.