Technology like computers, TV and cellphones has tremendously reduced the amount and quality of sleep that children and teens get compared to 20 years ago, a Canadian pediatrician says.

Recent data suggests that 60 per cent of teens will keep their cellphone in their room and respond to a text at night, said Dr. Indra Narang of the Hospital for Sick Children in Toronto.

The average teen should get nine hours of sleep, but the medical literature and research at SickKids suggest they get only about seven hours.

The number of hours alone isn't the only important factor, Narang stressed. Children who are sleep-deprived or who have sleep disturbance can have problems with behaviour and learning and may not do as well at school as expected.

"We have some data from here at SickKids that showed that children who sleep less and have sleep disturbance, and this was in over 4,000 adolescents, that sleep disturbance was independently linked to other factors such as high blood pressure, high cholesterol levels and perhaps even an increase in their weight," said Narang, who studies sleep disordered breathing and childhood narcolepsy.

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Parents could remove cellphones from their teen's bedroom at night to avoid sleep disturbances from text messages. (iStock)

Suggestions for parents:

  • Establish a sleep routine that includes winding down after dinner before going to sleep — avoidance of  television, no cellphones and no video games so the body and brain unwind and prepare for slumber.
  • Keep a set bedtime and a set wake-up time that spills over into the weekend.
  • Take devices like cellphones out of the bedroom at light's out.
  • Keep the house quiet.
  • Avoid bright lights in the bedroom. Night lights are OK.

"The key message to parents with children of all ages is routine. A sleep routine is very, very important and this isn't just getting a certain number of hours of sleep," Narang advised.

Shaista Justin of Toronto has a son and daughter in elementary school.

"Sometimes I think they're asleep and then when I check in on them, I see that there's a big comforter over them. When I pull it away,  I see an iPod," said Justin, who then removes the device.

With files from CBC's Kim Brunhuber