Non-Environmental Cost-Benefit News

Stents are tiny metal scaffolds inserted in the artery after angioplasty -- a procedure in which a little balloon is used to clear out plaque that can trigger a heart attack.

While stents keep arteries open, they can, paradoxically, increase the risk of the artery reclosing, a condition called restenosis. To address this problem, scientists developed stents coated with drugs that reduce the risk of restenosis.

But drug-eluting stents cost about $2,900 each, compared to $500 for a traditional stent. Angioplasty patients receive, on average, 1.4 stents.

The question for the cash-strapped health system then becomes: Is the additional cost worth it?

A series of papers published in a recent edition of the Canadian Medical Association Journal demonstrates just how difficult it is to answer that sort of question -- and these questions are arising with increasing frequency as new technologies come along.

A team led by Fiona Shrive, a researcher in the department of community health sciences at the University of Calgary, calculated that to extend a person's life by one year -- a measure called a QALY, or quality-adjusted life year -- using a drug-eluting stent costs $58,721 (includes price of operation plus medical care.)

Generally speaking, an intervention -- be it a drug, surgery or prevention program -- with a cost per QALY of less than $50,000 is deemed cost effective. That means that across-the-board use of drug-eluting stents would not be a good investment, at least not at their current price.

But Ms. Shrive and her research team dug further and found that using drug-eluting stents for diabetics and people over the age of 75 produced costs per QALY of $44,135 and $40,129 respectively. In other words, it makes good economic sense to use drug-eluting stents, but selectively.

"It's not an either/or question on whether we should use this new technology," said Dr. William Ghali, co-author of the paper and a professor of community health sciences at the U of C.

"A tailored strategy is a much more reasonable and efficient use than across the board."

Dr. Ghali said there is anecdotal evidence that drug-eluting stents are being used selectively, but there do not appear to be explicit policies in place.

About 35,000 angioplasties are performed in Canada annually, and almost all patients get stents. It is not clear, however, what percentage get drug-eluting stents.

Dr. Ghali underscored the difficulties that arise in adapting new technologies with a personal anecdote, saying that, as a researcher, he is "not an enthusiast of drug-eluting stents," but if he were a patient, he would definitely want one.

"Does asking for it justify getting it?" he wondered.

Dr. Ghali also stressed that the cost per QALY calculation, while a good tool, does not take into account where extra money would come from in a cardiology program with limited resources.

In a commentary also published in the Canadian Medical Association Journal, Dr. James Brophy of the division of cardiology and epidemiology at Royal Victoria Hospital in Montreal said a switch to drug-eluting stents would cost at least $75-million more and provide only marginal benefits.

He noted that for all the touted benefits, drug-eluting stents do not reduce the risk of heart attack or death. And while the newer devices do reduce the risk of restenosis and the need for a second surgery, that is only a concern for a small minority of patients.

In the new research, derived from a large database of cardiac patients in Alberta, 8.2 per cent of patients undergoing angioplasty needed a second operation.

"About 90 per cent of patients do not experience clinical restenosis with conventional stents and therefore would not derive any additional benefit from having a sirolimus-eluting stent," Dr. Brophy said. (Sirolimus is the chemical used to coat stents; there are also stents available that are coated with paclitaxel.)

He added that a good number of repeat surgeries are likely due to disease progression, not restenosis, so drug-eluting stents would not make a difference.

Dr. Brophy said the debate about the value of new technologies should be a broader one, comparing the costs and benefits of prevention programs and simple, proven treatments. (Aggressively treating diabetics with blood pressure medication, for example, has a cost per QALY of $1,959, and that approach could delay or prevent a number of surgeries.)

"Our current infatuation with interventional cardiology must be questioned," Dr. Brophy said, arguing that money is better spent on primary and secondary prevention programs than on fancy bells and whistles like drug-eluting stent

By ANDRÉ PICARD, Page A15
The Globe and Mail (Candada) www.theglobeandmail.com
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