“I choose not to keep my story private because there are many women who do not know that they might be living under the shadow of cancer. It is my hope that they, too, will be able to get gene tested, and that if they have a high risk they, too, will know that they have strong options.”

Those were the words of Angelina Jolie in May 2013, when the high-profile actress and humanitarian wrote an op-ed in the New York Times publicizing her decision to undergo prophylactic bilateral (aka “preventive double”) mastectomy. Genetic testing had shown she carried the troublesome BRCA1 gene. This, combined with her family history of cancer—her mother died of the disease at 56—sharply increased her odds of getting breast cancer.

A new study shows that her encouragement of women to be similarly proactive resonated with more than a few.

Led by Kami Kosenko, PhD, an associate professor of communication at North Carolina State University, the study’s authors posted an online questionnaire to gauge the influence of Jolie’s decision immediately after its announcement. Some 356 women completed the form; of these, 295 said they were aware of Jolie’s announcement.

After whittling the group to 229 qualified participants, the researchers found that nearly one-third—30 percent—intended to get tested to see if they carried the BRCA1 gene. (Some 23 percent said “probably” while 7 percent said “definitely.”)

The results were posted online July 20 in the Journal of Health Communication.

In their study abstract, Kosenko and colleagues said they were guided by a “model of celebrity influence” as they assessed study participants’ demographics and health history, identification and parasocial interaction with Jolie.

“Women who identified more strongly with Jolie were more likely to intend to get the genetic testing regardless of whether they had a family history of cancer than women who did have a family history of cancer but did not identify with Jolie,” said Kosenko in a news release. “The same was true of women who felt they had some sort of parasocial relationship with Jolie, meaning they viewed her as a friend. This means that Jolie’s speaking out definitely had an impact.”

The study put compelling numbers to anecdotal evidence of an “Angelina Effect” as speculated in a 2013 Time magazine cover story.

The hard evidence is preliminary, and more work needs to be done “to help us understand what makes a celebrity relatable,” said Kosenko. “For example, in our survey, non-white women were more likely to identify with Jolie than white women were. Why is that? We don’t know.”

Click here to access the full study.