About one per cent of Canadians account for a third of health-care costs, and there are striking differences by age group, say researchers who hope the findings will help doctors to meet patient needs.

Their findings, published Monday in the Canadian Medical Association Journal, were based on almost 15 million people in Ontario who were eligible for health-care funding between 2009 and 2011.

The study revealed how health-care spending is concentrated among high-cost users in different age groups and with different illnesses. Researchers did not undertake the study as a cost-saving exercise but to help plan policies to better meet patient needs, said study author Dr. David Henry of the Dalla Lana School of Public Health at the University of Toronto.

"We need to better predict who's going to become a high-cost user," Henry said. "We need to be much better at doing that for their sake and for society's sake."

For Henry, the breakdowns by age group were revealing.

Among children and teens, nearly 40 per cent of total spending was focused on the top one per cent of users, who cost about $8,000 per person annually. The reasons included low-birth weight and prematurity that require neonatal intensive care, lengthy treatment for depression for some teens, and chemotherapy for cancer.

For those aged 18 to 64, chronic diseases such as atherosclerosis or hardening of the arteries, congestive heart failure with heart damage, and the requirement for palliative care, cost about $22,000 per person a year. Those in the top one per cent accounted for 36 per cent of total spending.

For those over 65, the top one per cent accounted for 16 per cent of total expenditures, about $83,000 per person annually. The reasons included congestive heart failure, chronic lung disease, hip fractures and pneumonia.

Better transitions

Costs were less concentrated among those in the oldest age group, said Henry, who is also a researcher at the Institute for Clinical Evaluative Sciences (ICES).

"The majority of over 65s don't cost the health-care system very much. As long as we keep ourselves in good health and many people try very hard to do that, then it will work."

Henry said if medical and social interventions are focused on those at risk of becoming sick with chronic disease then it's hoped they'll stay out of hospital and long-term care while maintaining quality of life with reasonable symptom control.

The findings highlight how little health care the average person uses, said Dr. Rick Glazier, a family physician at St. Michael's Hospital in Toronto and ICES scientist who was not involved in the study.

For Glazier, the research points to how fragmented the health-care system remains. It's a frustration that comes to the fore during transitions in care, such as when someone is discharged from hospital and doesn't bring the discharge summary to their next appointment. 

"A lot of time and effort is just starting now to go into figure out how to manage those transitions better," Glazier said. "For the public, it's an area of our health system that isn't  functioning all that well, but there's a real hope for."

The Ontario government spent $42 billion on health care in 2009. About 75 per cent of the funds were for individuals and the rest on public health, community service agencies and administration.

Previous Canadian data has shown that spending has been concentrated on high-cost users for decades.

With files from CBC's Amina Zafar