Do celebrity endorsements matter? Observational study of BRCA gene testing and mastectomy rates after Angelina Jolie's New York Times editorial

OBJECTIVE To examine the effect on BRCA testing and mastectomy rates of a widely viewed 2013 New York Times editorial by public figure Angelina Jolie that endorsed BRCA testing and announced Jolie's decision to undergo preventive mastectomy. DESIGN Observational study with difference-in-difference analysis. SETTING Commercially insured US population. PARTICIPANTS Women aged 18-64 years with claims in the Truven MarketScan commercial claims database (n= 9 532 836). MAIN OUTCOME MEASURES Changes in BRCA testing rates in the 15 business days before versus after 14 May 2013 (editorial date) compared with the change in the same period in 2012; mastectomy rates in the months before and after publication, both overall and within 60 days of BRCA testing among women who were tested; national estimates of incremental tests and expenditures associated with Jolie's article in the 15 days after publication. RESULTS Daily BRCA test rates increased immediately after the 2013 editorial, from 0.71 tests/100 000 women in the 15 business days before to 1.13 tests/100 000 women in the 15 business days after publication. In comparison, daily test rates were similar in the same period in 2012 (0.58/100 000 women in the 15 business days before 14 May versus 0.55/100 000 women in the 15 business days after), implying a difference-in-difference absolute daily increase of 0.45 tests/100 000 women or a 64% relative increase (P<0.001). The editorial was associated with an estimated increase of 4500 BRCA tests and $13.5m (10.8m; pound (sic)12.8) expenditure nationally among commercially insured adult women in those 15 days. Increased BRCA testing rates were sustained throughout 2013. Overall mastectomy rates remained unchanged in the months after publication, but 60 day mastectomy rates among women who had a BRCA test fell from 10% in the months before publication to 7% in the months after publication, suggesting that women who underwent tests as a result of to the editorial had a lower pre-test probability of having the BRCA mutation than women tested before the editorial. CONCLUSIONS Celebrity endorsements can have a large and immediate effect on use of health services. Such announcements can be a low cost means of reaching a broad audience quickly, but they may not effectively target the subpopulations that are most at risk for the relevant underlying condition.