Actress Angelina Jolie’s 2013 announcement detailing her decision to undergo a mastectomy to reduce her risk of developing breast cancer likely inspired more women in English-speaking countries to do the same, according to a new study by researchers at Weill Cornell Medicine and the University of New South Wales, Australia.

Using hospital discharge data from New York state and New South Wales from 2004 to 2014 to examine trends in risk-reducing mastectomy (RRM), the researchers identified a significant increase in procedures starting in May 2013, three months after Jolie’s announcement. They say their findings, published Sept. 25 in Health Services Research, reveal celebrities have power to influence the health care decisions of the general public, and health care professionals should leverage this effect by offering more information about treatment options, especially in regard to genetic testing results.

“This is an important area of research that health care providers and policymakers need to pay attention to,” said Art Sedrakyan, a professor of health care policy and research at Weill Cornell Medicine. “If celebrities are going to act on genetic testing and announce their treatment choices, then we should get prepared on our end to assess public health impact.”

The study found that 20 months before Jolie’s announcement, there were an average of 3.3 bimonthly RRM cases per 1 million women in New York; 20 months after the announcement, there were an average of 6.3 bimonthly RRM cases per 1 million women in New York. Rates of RRM in New South Wales were relatively similar.

A 2015 U.K. study showed an increase of RRM after Jolie’s announcement, but this new study shows correlation in two separate English-speaking countries, which also helps rule out local influences on RRM rates, said Jialin Mao, an instructor of health care policy and research at Weill Cornell Medicine. It also validates previous studies that showed singer Kylie Minogue’s 2005 breast cancer diagnosis led to an increase in breast imaging among Australian women age 25-44.

The researchers, including Louisa Jorm, the Foundation Director of the Centre for Big Data Research in Health at the University of New South Wales, say health professionals should be more proactive when celebrities announce personal health news, so that information about treatment, risk and cost is distributed clearly to the public.

“Both the ‘Kylie Effect’ and the ‘Jolie Effect’ demonstrate the power of celebrity illness and treatment to generate intense media coverage and change consumer behavior,” Jorm said.

Timothy Malcolm is a freelance writer for Weill Cornell Medicine.