U OF T study finds significant unmet need for arthroplasty, even in high utilization areas

A significant number of people in Ontario who might benefit from joint replacement surgery to ease the pain and functional limitations of severe arthritis are not receiving the procedure, according to a landmark University of Toronto study of clinical severity and patient preference in total joint replacement.

The study, principally funded by the Canadian Institutes of Health Research, examined patients in two distinct areas of the province - Oxford County, in southwestern Ontario, which has a high rate of arthroplasty and East York, in the City of Toronto, where the rate is much lower. To the surprise of the researchers, not only did the area of high utlization still have a 27 per cent greater prevalence of severe osteoarthritis, ie. more potential arthroplasty candidates, but the proportion of people with severe arthritis who were willing to undergo total joint replacement surgery was almost two times greater than in the low rate area. As a result, although there was unmet need for arthroplasty in both areas, it was significantly higher in the high-rate area.

"We can no longer assume that an area that has a high rate of utilization of a medical service, in this case arthroplasty, is inappropriately overusing that procedure," says the study's lead author, Professor Gillian Hawker, director of the clinical epidemiology program in U of T's Faculty of Medicine and a rheumatologist at Sunnybrook and Women's College Health Sciences Centre. "Once you take need and willingness into consideration, the area variation is expected."

The researchers contacted all 55-year-olds in the two areas using a three-stage survey technique to estimate the prevalence of moderate to severe arthritis and the willingness of these patients to have total joint replacement. Among those with severe arthritis, only 15 per cent in the high rate area were definitely willing to undergo arthroplasty - that number falls to 9 per cent in the low rate area. According to the authors, this emphasizes the importance of considering both patients' preferences and surgical indications when evaluating need and appropriateness for surgery.

"Wide variations in the use of healthcare services from one region to the next have been viewed as a concern because they display potentially unequal access to healthcare services," says Professor Peter Coyte, a health economist at U of T and one of the study's co-authors. "As it turns out, these variations may have more to do with people willing to go ahead with surgery once they've reached a particular threshold and should not necessarily be viewed as problematic."

According to Hawker, researchers need to better understand how willingness and need are defined so that the process can be applied to other medicare services. "Once we've done this, we can look at health services other than joint replacement and better understand what we need to do in terms of allocating health services and resources to better meet the needs of the population," says Hawker, also a member of the Canadian Arthritis Network and senior scientist with the Arthritis Community Research and Evaluation Unit (ACREU).

Arthritis is the most frequent cause of long-term physical disability in Canada, affecting one in 40 Canadians. A recently published study by ACREU projects that the number of Canadians with arthritis and related disabilities will more than double by 2031, with half of this increase occurring among Canadians aged 45 to 64. According to the Canadian Arthritis Network, more than 50 per cent of Canadians of working age with arthritis-related disabilities are forced to leave the labour force because of their condition. Arthroplasty is among the most cost-effective interventions in medicine.

This study, published in the March issue of Medical Care, also received support from the Arthritis Society of Canada, Physicians' Services Inc. Foundation, the Canadian Orthopedic Foundation and the University of Toronto Dean's Fund.

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Steven de Sousa
U of T Public Affairs
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steven.desousa@utoronto.ca
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