Some hospitals may specialize only in short-term or outpatient therapy for low-risk patients.

"We hardly ever see any low-risk patients," Dr. Matshe said.

In other hospitals the sort of low-risk patients that Shouldice operates on are sent home the same day without overnight hospitalization.

"All the other trials that I'm aware of are really in quite low-risk patients, and so they just aren't comparable," he said.

For example, a low-risk patient must have a larger induration for a positive than a high-risk patient.

Stress cardiac imaging is not recommended for asymptomatic, low-risk patients as part of their routine care.

In low-risk young patients, the thalassemia-free survival rate is 87%; the mortality risk is 3%.

That's why many doctors advise low-risk patients to wait until they're 40 when their breast tissue is, um, less dense.

In most cases this has meant the use of such low-risk patients that the number of arrhythmic events has been too low to allow any valid conclusions.

This tells me," he said, "there is probably an opportunity to lower the rate of Caesareans, at least among ordinary low-risk patients.