Medical tourism and medical data

An Op-Ed in the NY Times reports on the difficulty of evaluating how well foreign hospitals do compared to American hospitals: Overseas, Under the Knife . A big difficulty is that appropriate data aren't collected on medical outcomes:

"There is reason to think the quality of care at some foreign hospitals may be comparable to quality in the United States. More than 200 offshore hospitals have been accredited by the Joint Commission International, an arm of the organization that accredits American hospitals. Many employ English-speaking surgeons who trained at Western medical schools and teaching hospitals.
So should offshore surgery be welcomed as a modest way to make American health care more affordable? We can’t know until we can directly compare the outcomes with those of American surgery. To begin, we must adopt a uniform way for American hospitals and surgeons to report on the frequency of short-term surgical complications.
Medicare could do this by requiring that all participating hospitals and surgeons count pre-surgical risk factors and post-surgical complications during hospitalization and for 30 days afterward, when most short-term problems become evident. The system used for many years by Veterans Affairs hospitals to reduce surgical complications is the best option for this, since it is available to all American doctors through the American College of Surgeons. So far, however, only a small minority of surgeons participate in this or any other valid national system of reporting surgical outcomes.
Patients and their surgeons also need comparable measurements of long-term success. Medicare should lead by adopting Sweden’s method of monitoring hip joint replacement outcomes. It tracks, for example, a patient’s ability to walk without pain six years after surgery.
Finally, Medicare should invite accredited offshore hospitals and their affiliated doctors to participate in all of its comparative performance reporting systems. Beyond informing Americans contemplating treatment abroad, such comparisons would allow us to learn if our care is the world’s best — and to accelerate our improvement efforts if it is not. "

Agreeing on what data to collect, and collecting it, isn't easy. (And of course what data you collect can influence what outcomes you get in ways that aren't all desirable.) But the lack of outcome data is a weak link in American medicine, which makes it difficult to evaluate alternative practices and procedures. I see this in discussions about kidney exchange, and my guess is that this is a big problem in improving medicine and the medical marketplace generally.