Published August 03, 2011
Major U.S.-sponsored clinical trials on heart disease often turn to other countries to recruit patients and a new report questions whether that undermines the evidence they generate and the health of the American clinical trial system.
Researchers found that of 24 U.S. taxpayer-funded clinical trials on heart disease in the past decade, 19 included patients from other countries. Across 11 of those studies, international patients accounted for nearly half of participants.
That high international involvement raises several concerns, according to Dr. Venu Menon and his colleagues at the Cleveland Clinic in Ohio.
One is whether the results of a trial that includes people from other nations -- and possibly with varied demographics, lifestyle habits and healthcare systems -- can be reliably applied to the U.S. population.
"There are a number of benefits to international participation in these clinical trials," Menon told Reuters Health in an interview. "But one thing we need to be sure of is that the results will be generalizable to U.S. patients. That may not occur if the trial patients don't reflect the U.S. population."
But the acting director of the U.S. agency that funds those trials had no worries about the usefulness of the results.
"I totally disagree with that (concern)," said Dr. Susan Shurin of the National Heart, Lung, and Blood Institute (NHLBI).
"We don't see international participation in clinical trials as a negative at all," she said in an interview.
Shurin pointed out that Canada has been the top international collaborator in NHLBI-funded trials on heart disease. And the demographics there, she said, are similar to those in the U.S.
Menon agreed that "Canada is where we'd have the least concerns" about study findings' relevance to U.S. patients.
But he added that the U.S. and Canada "certainly have different health systems," and there are other differences that could be relevant to the effects of a given heart disease treatment:
Canadians tend to weigh less, for example, and are less likely to have ever undergone invasive heart procedures.
There is also the question of whether far-flung research sites can be expected to follow the ethics and standards of conduct required in NHLBI-funded studies, according to Menon's team.
Again, Menon noted, no one is worried about Canada or other countries well-established in clinical research. But, he said, concerns have been raised about developing nations where there is little experience in conducting clinical trials.
Across the 24 NHLBI trials the researchers studied, international patients mainly came from Canada, Western Europe, Australia and New Zealand. But a few included sites in Latin America and Eastern European countries like Russia and the Czech Republic.Shurin said that the NHLBI has oversight of all of these trials.
"We're heavily involved in them," she said. "And our observation has been that the conduct and performance at these sites is every bit as good as it is in the U.S."
But why do U.S.-funded trials turn to other countries for patients? In the most recent trial Menon's team assessed -- one published in 2009 in the New England Journal of Medicine -- 80 percent of the 1,000 heart failure patients participating in the trial were outside the U.S.
Often, it's because the studies cannot get enough U.S. patients to participate, according to Shurin -- which brings up an issue on which there does seem to be agreement: the need to get Americans into major clinical trials.
An editorial published with the study argues that changes are needed to ensure that U.S. clinical research doesn't go "offshore" in the way so many other industries have done.
"We must focus our attention on fixing our own system," write Drs. Robert M. Califf and Robert A. Harrington of Duke University School of Medicine.
Among the problems, they say, is that the process of conducting a clinical trial in the U.S. has become too inefficient, expensive and cumbersome -- and doctors throughout the country have little incentive to enroll their patients in studies.
Both Shurin and Menon agreed.
Shurin pointed out that in a country like Canada, the UK or Germany with universal healthcare systems, doctors make the same amount of money whether they enroll a patient in a clinical trial or not. A cardiologist in the U.S., however, stands to lose money.
"There is very little incentive for clinicians," Menon said. "It doesn't give them monetary rewards or help in career advancement."
As far as career advancement, Menon noted that the lead investigator on a clinical trial stands to benefit. "But they aren't the people enrolling patients," he said.
The doctors who are, spread out at different centers around the U.S., "don't get any recognition," Menon said.
He also said that medical institutions, starting with medical schools, need to begin putting more value on clinical research -- so that more doctors see the importance of collecting data on patients and making sure that their care is actually based on strong evidence that it works.
In heart disease treatment, only about 15 percent of official "guideline recommendations" are actually based on results from definitive clinical trials, Califf and Harrington point out.
That, Shurin said, certainly highlights the importance of continuing to do large, rigorous clinical trials -- and getting patients to enroll in them.
For its part, the NHLBI is looking at ways to make the clinical trial process "less burdensome," Shurin noted.
Some well-intended regulatory hurdles that have come up in recent years could be too much, Menon said -- referring to things like specific training requirements for nurses and others involved in a study, and documentation rules that have added to administrative time and costs.
As for patients, Menon said it's important to make them aware that clinical trials are vital for understanding the benefits, and risks, of medical treatments -- so they can at least consider participating in one.
"I think they should know that if a trial is being sponsored by the National Institutes of Health, then it's a really important question that is being studied," Menon said.
They can also feel "reassured," he added, that the conduct of the study will be tightly overseen.
Shurin, though, said she doesn't see reluctance on the part of patients as being a major reason for low U.S. enrollment in clinical trials. "Our usual experience," she said, "is that many people are more than willing to participate."