Toward the end of my general surgery training, a senior surgeon pulled me aside to ask about my plans for further training. One of the best surgeons in the hospital, he had done his own subspecialty training at a hospital famous for vascular surgery.

He nodded in approval when I told him where I was going; the hospital was known for excellent results with sick patients undergoing difficult operations.

“Any advice?” I asked.

The surgeon leaned over. “Learn about their system,” he said. He smiled for a moment as if recalling his own training, then added: “It’s not the techniques or the fancy equipment. It’s how they do things, it’s their culture that makes them really great.”

At the time, I didn’t believe him. I was convinced the hospital had superior results because the surgeons were so good. And I was eager to learn to operate like them.

But I had only been working there a short time when it became clear that in day-to-day patient care, good or even superb operative skills weren’t enough to make a hospital’s reputation. It was having a well-oiled team of clinicians who believed in supporting one another and doing their best.

Hospitals have long vied for the greatest clinical reputation, and recent efforts to increase public accountability by publishing hospital results have added a statistical dimension to this battle of the health care titans. Information from most hospitals on mortality rates, readmissions and patient satisfaction is readily available on the Internet. A quick click of the green “compare” button on the “Hospital Compare” Web site operated by the Department of Health and Human Services gives any potential patient, or competitor, side-by-side lists of statistics from rival institutions that leaves little to the imagination.

The upside of such transparency is that hospitals all over the country are eager to improve their patient outcomes. The downside is that no one really knows how.

Hospitals have made huge investments in the latest and greatest in clinical care — efficient electronic medical records systems, “superstar” physicians and world-class rehabilitation services. Nonetheless, large discrepancies persist between the highest- and lowest-performing institutions, even with one of the starkest of the available statistics: patient deaths from heart attacks.

Why is that?

According to a study released this week in The Annals of Internal Medicine, the answer to the decade-long conundrum may have little to do with investing in high-tech equipment and evidence-based protocols. Instead, improving patient outcomes may require first investing in and focusing on the culture of the organization itself.

Over the course of a year, the researchers visited 11 hospitals that ranked in either the top 5 percent or the bottom 5 percent in mortality rates for heart attacks, and conducted more than 150 in-depth interviews with key administrators, doctors, nurses, pharmacists, quality management staff and other health care workers. The researchers then correlated hospital performance statistics with recurrent themes in the interviews and found that what really mattered was simply this: a cohesive organizational vision that focused on communication and support of all efforts to improve care.

“It’s how people communicate, the level of support and the organizational culture that trump any single intervention or any single strategy that hospitals frequently adopt,” said Elizabeth H. Bradley, senior author and faculty director of the Yale Global Health Leadership Institute at Yale University.

While business executives have long understood the impact of an organization’s culture on the bottom line, it has not been clear if those same qualities could affect how well patients do. Earlier studies intimated otherwise, suggesting that factors like how rich or poor patients are, an affiliation with an academic medical center, the number of beds and an urban setting could account for the differences in hospital mortality rates.

But in this study and an earlier one, Dr. Bradley and her co-investigators found that these factors accounted for less than 20 percent of the variation between high- and low-performing hospitals. “A lot of people think that you have to go to a really big city teaching hospital with really expensive equipment,” Dr. Bradley said. “But we didn’t find that to be true.”

Rather, it was the approach to challenging patient care issues that seemed to set institutions apart. A hospital might discover, for example, that a heart attack patient who returned to the hospital with severe edema, or swelling, might have been discharged without her prescribed diuretic.

At a low-performing hospital, such an error might result in doctors, nurses and pharmacists on the front lines blaming one another and hospital leaders taking care to remain uninvolved. But clinicians and leaders at a high-performing hospital would be eager to address the error, acknowledging it without disparaging one another and working together to re-examine and, if necessary, reconfigure the hospital’s discharge process.

“The difference is very powerful,” Dr. Bradley noted. “Even top hospitals had problems that would make your hair stand on end; but then it’s like choreography when they all get together to figure out what went wrong.”

Dr. Bradley’s team is studying a larger group of hospitals, including those that fall in the middle of the pack, to see if their initial findings still hold. If they do, their research could change how hospitals invest in patient care and how clinicians view their work.

“We have to focus on the relationships inside the hospital and be committed to making the organization work,” Dr. Bradley said. “It isn’t expensive and it isn’t rocket science, but it requires a real commitment from everyone.”