“I’m a skeptic of the one-size-fits-all, four-drugs-for-everyone approach,” said Dr. Steven E. Nissen, head of the department of cardiovascular medicine at the Cleveland Clinic. “It runs counter to what most of us in the U.S. consider good medical practice.”

Simple tests, including cholesterol tests that use only a finger prick, are available, he noted.

Dr. Thomas R. Frieden, a former director of the Centers for Disease Control and Prevention and now the president of Resolve to Save Lives, an organization that seeks to lower worldwide cardiac deaths, said he thought a four-drug pill like the one used in the study was appropriate only for people who had suffered a cardiac event.

Some blood pressure medications are safe enough to give to untested people, he said. But aspirin, which can cause bleeding in the brain, is not; and statins, which can, in rare cases, cause liver and muscle damage, may not be.

The Iran study was conducted by doctors from Tehran University, the University of Birmingham in Britain and other institutions.

It was the first study of such a multidrug pill that was large and long-lasting enough to measure “clinical outcomes” — how many people actually had heart attacks, strokes or episodes of heart failure while taking the pills, rather than just how many, for example, lowered their blood pressure or cholesterol.

Similar studies are underway in many countries.

However, since there is so much controversy about the ingredients used in the medication, each study has its own pill recipe.

Dr. Yusuf is leading the TIPS 3 trial on about 5,700 people in Bangladesh, Canada, Colombia, India, Malaysia, the Philippines, Tanzania and Tunisia; it uses a pill containing three blood-pressure drugs and a statin. (The trial’s three other “arms” use low-dose aspirin, vitamin D and a placebo pill.) It is expected to end in March .