new study could add to the argument over equal pay in the ranks of medicine: Older patients treated by female doctors tend to do better than those treated by males.

Public health researchers at Harvard found that elderly patients were less likely to die or be readmitted to the hospital within 30 days if treated by female doctors rather than male. The study doesn’t explain why this happens, but prior studieshave found that female doctors tend to spend more time with patients, communicate better, and follow clinical guidelines more often than their male colleagues.

The findings not only launch a grenade at the gender pay gap in medicine, they also suggest the methods of female physicians—if replicated broadly—could significantly improve the quality of medical care in the United States.

“We need to understand why these differences exist … and figure out how to translate it to the broader population of physicians,” said Dr. Ashish Jha, a professor of health policy at Harvard T.H. Chan School of Public Health and senior author of the paper.

The study, which examined data from more than 1 million Medicare beneficiaries, said that if male doctors achieved the same outcomes as female doctors, annual deaths of Medicare patients alone would drop by 32,000. That’s comparable to the number of annual deaths from car accidents in the US.

Meanwhile, female physicians are still paid considerably less than males, according to recent research. A paper published this year in JAMA Internal Medicine found that male academic physicians get an average of 8 percent more than females, regardless of specialty, years of experience or productivity, which translates to an average salary bump of about $20,000, although the extent of the disparity varies widely. 

Jha said he hopes the study will spur constructive conversation. The wage gap “is particularly unconscionable given the performance of women in terms of providing high quality care,” he said.

Harvard’s study found that, when treated by female internists, Medicare patients had a 4 percent lower relative risk of dying prematurely and 5 percent lower risk of being readmitted to a hospital within 30 days. Researchers examined outcome data between 2011 and 2014 on the eight most common conditions in seniors treated by general internists, including sepsis, pneumonia, congestive heart failure, and acute renal failure.

Patients of female physicians had lower rates of mortality and readmission in all of the conditions examined, although the difference was not always statistically significant. Sepsis is a leading killer of elderly patients and costs more than $20 billion a year to treat. It killed about 182,000 people in the United States in 2014, according to the Centers for Disease Control and Prevention, which launched a national campaign this year to improve treatment of the condition.

The study reported that mortality rates for sepsis were more than 2 percent lower among patients treated by female physicians, and about 1 percent lower for those treated for heart arrhythmia and pneumonia. Female doctors recorded about 1 percent lower readmissions for pneumonia and congestive heart failure. That might not seem like a big difference, but the costs add up quickly when applied to tens of thousands of patients with these conditions.

Jha said the researchers sought to control for a variety of factors, including risk adjusting for the demographics of patients and accounting for differences in the size and types of hospitals where the physicians worked. They also tested the findings by restricting the analysis to hospitalists, to whom patients are randomly assigned, to make sure patient selection of doctors was not skewing the results.

The outcomes remained consistent in that population as well.

“We spent quite a bit of time trying to make sure the findings were robust,” he said. “I feel very confident that findings are real and that it probably says something important about the way men and women are practicing.”

Several studies have examined those differences in recent years in different types of physicians. Johns Hopkins researchers found that female primary care physicians engage in more communication that focuses on the individual needs of the patient; researchers also found they have longer visits than their male counterparts.

More effective communication has been linked with higher rates of patient satisfaction, lower readmissions, and better adherence to therapeutic recommendations. Hospitals nationwide are seeking to improve physicians’ communication with patients, especially as they face financial penalties for readmissions. The task is particularly challenging among elderly patients, who see an average of seven physicians a year across four different practices, according to the Institute of Medicine. 

Republished with permission from STAT. This article originally appeared on December 19, 2016