Parents who set rules about bedtime can help their children to get more sleep, according to new Canadian research.

Researchers at Public Health Ontario used data from 1,622 parents with at least one child under the age of 18 years old, and looked at how many children were meeting the Canadian sleep guidelines.

Based on parents' reports, and depending on the age of the child, the team found that 68.3 to 92.6 per cent of children met the guidelines for sleep on weekdays, and 49.3 to 86 per cent for weekends.

Although the number of children meeting the guidelines increased between ages 5 and 9 years, it declined between 10 and 17 years, with children aged 15 years old showing the greatest difference between weekday and weekend sleep. At this age, 38.3 per cent fewer children met the guidelines on the weekends compared to the weekdays.

However, when it came to parental influence on sleep, around 94 per cent reported encouraging their child to go to bed at a specific time, and just over 84 per cent reported enforcing these times, suggesting that parents are aware of the benefits of a good night's sleep, and in favour of it.

But it appeared that despite all the good intentions of those encouraging bedtime rules, it was enforcing them that had the biggest effect, with children of parents who were strict with bedtime 59 per cent more likely to meet sleep guidelines on a weekday.

However, neither encouraging nor enforcing bedtimes had an effect on sleep on the weekend.

Perhaps surprisingly, the team also found that neither encouragement nor enforcing rules on screen time in the bedroom were reported by parents as having an effect on children's sleep.

"This is particularly surprising in light of the evidence showing screens in the bedroom can negatively affect children's sleep," commented senior author Dr. Heather Manson.

The team pointed out that there were some limitations of the study, including using self-reported data from the parents, which can be unreliable, and not including any direct measures of sleep duration or sleep quality in their survey, which are important components of 'healthy' sleep.

However, Dr. Manson still concluded that parents enforcing a bedtime on weekdays, rather than just encouraging, is still a way to help support children to achieve a sufficient amount of sleep.

The findings can be found online published in the journal BMC Public Health.