OTTAWA - Asthma cases have dropped among two- to seven-year-olds to their lowest level in more than a decade, Statistics Canada reported Wednesday.

One factor that may have contributed to the decline is the hand-in-hand drop in smoking rates across the country, along with changes in diagnosis patterns, experts say.

The percentage of kids with asthma rose from 11 per cent to 13 per cent from 1994 to 2001, but by last year, the figure had fallen to 10 per cent.

Since the turn of the century, the percentage of kids with asthma has fallen in the Atlantic provinces, Ontario and Quebec, but remained fairly stable in the Prairie provinces and British Columbia, the study showed.

Dr. Allan Becker, a pediatric allergist, said the overall findings don't surprise him.

"There are two things that I think are probably going on. One is that we may actually be seeing a real plateau in asthma prevalence, and that's entirely possible," he said from Winnipeg, where he is head of the section of Allergy and Clinical Immunology in the department of pediatrics and child health at the University of Manitoba.

"And secondly that there is that diagnostic perception now that not all that wheezes is asthma. That's an aphorism that we've heard from our professors many, many, many years ago, mostly speaking about adults. But now that's equally true in terms of children."

The study found that a significantly higher percentage of boys than girls had been diagnosed with asthma over the 14-year period. The upturn in asthma prevalence to 2000 and the decline that followed was seen in all age groups.

Becker said "there's no question" that a decline in smoking rates helps.

"Children of parents who smoke have a much higher frequency of colds, of respiratory infections, and among those children, the viral illnesses are the major causes of these wheezing illnesses," he said.

"And that would suggest, then, a diagnosis of asthma. So with fewer -- especially young parents -- smoking, it really does make a difference in the likelihood that these children will have wheezy episodes with their colds."

As well, he remarked on a greater tendency for people who do smoke to have their cigarette break outside.

"We believe that they are smoking more often out of doors and not in enclosed spaces, and that seems to hold true certainly when children are ill," Becker said.

"Whether it holds as true when the children are healthy for a period of time is still somewhat debatable."

A key finding is that the percentage of children with asthma who reported an asthma attack in the past 12 months fell steadily from 53 per cent in the mid-1990s to 36 per cent last year.

Becker gives credit to education targeted at children, their families, primary care physicians and pediatricians, who are doing an "excellent job" in helping to control asthma.

But he said it's not as good as it should be.

"We still have far too many children being seen in the emergency departments because of asthma flare-ups and too many children being admitted to hospital," he said.

"But it has progressively decreased since the late 1990s in Manitoba, and our hospitalizations for asthma are now one-third of what they were in the mid-1990s."

Statistics Canada said that besides the decline in smoking, environmental factors may be related to the recent decline in asthma rates -- such as improvements in air quality and changes in hygiene practices.

Becker noted that greater efforts are being made to avoid triggers and use medications appropriately.

But he said there's still severe morbidity of children ending up in emergency rooms, and it's unacceptable that there are about 300 deaths a year in Canada from asthma.

"There's a long way to go, but I believe we're on the right path in understanding asthma better and in helping children and their families manage asthma better."

The Statistics Canada study also found that the prevalence of upper-respiratory infections in children aged two to three years had dropped to 23 per cent last year from 26 per cent in 1995.

And the prevalence of young kids who had at least one middle-ear infection or inflammation had dropped to 50 per cent from 67 per cent in 1995.