A new Canadian study shows boys and young men are more likely to die than girls and young women, and they have a greater chance of dying due to injury, particularly from age 14 onwards.

The study, published this month in the Journal of Epidemiology and Community Health, looked at 3.1 million children born in Ontario between 1990 and 2016 and examined who died and from what cause between the ages of one and 24.

Researchers excluded those who died in their first year of life, saying those deaths are generally due to congenital anomalies or other causes that are not readily preventable.

They found boys and young men had a greater tendency to die, especially starting at age 14, and were three times more likely to do so than young women by age 24.

Deaths due to injury also increased after age 14, while intentional causes such as suicide accounted for one in five male deaths from injury between the ages of 15-24, and one in six female deaths from injury in that age group.

The study says nearly half of injury deaths were due to accidental poisoning or overdose. Transport accidents were the second leading cause of injury-related death for all sexes from age 15 onwards, accounting for roughly a third.

But it notes not all deaths had a documented cause, and it was not known which were confirmed by autopsy or an on scene investigation. Some suicides can be misclassified as accidental poisonings, which could mean more teen deaths were due to suicide than the data reflect, the study says.

More mental health supports needed, lead author says

Lead author Dr. Joel Ray, a clinician-scientist at St. Michael's Hospital in Toronto, said the jump in deaths during adolescence, particularly in boys, is "likely" due to an increase in risk-taking behaviours, but said biological factors and changes may play a role in those behaviours as well.

In any case, the study shows more mental health supports are needed for teenagers and preteens, he said.

"We have this upswing [in deaths] right around this age in which we would argue strongly that a lot of these deaths are actually preventable and definitely untimely," said Ray, who is also affiliated with the Institute for Clinical Evaluative Sciences.

He said more research is also needed on poisonings and overdoses and the degree to which some are intention rather than accidental.