Trial of a Mammography Decision Aid for Women Aged 75 and Older

Women aged 75 and older are the fastest growing segment of the US population and breast cancer incidence increases with age. However, none of the randomized trials of mammography screening included women >74 years and it is not known if mammography helps these women live longer. Increasingly, data suggest that women need around 10 year life expectancy to have a chance at a mortality benefit from being screened with mammography. Meanwhile, there are immediate harms to screening older women including: pain, anxiety, complications from tests after a false positive mammogram (e.g., breast biopsy), and overdiagnosis (finding tumors that otherwise would never have caused symptoms in one's lifetime). Overdiagnosis is particularly concerning since some older women experience significant complications from breast cancer treatment. Guidelines state that there is insufficient evidence to recommend mammography screening for women aged 75 years or older and encourage clinicians to discuss the uncertainty about the balance of benefits and harms with older women. Yet, few older women are informed of potential harms of mammography before being screened, likely because explaining such uncertainty can be challenging and time consuming.

To improve older women's understanding of the benefits and risks of mammography screening, investigators previously developed and pilot tested a pamphlet decision aid (DA) on mammography screening for women aged 75+ years. The pilot pretest/posttest trial of 45 women 75+ years found that the DA resulted in older women being more knowledgeable about the benefits and risks of mammography, clearer in their values, and fewer intended to be screened, especially those with <10 year life expectancy.

Investigators now propose a large cluster randomized controlled trial (RCT) of the DA, using primary care physician (PCP) as the unit of randomization, to definitively evaluate the DA's efficacy. The investigators aim to recruit 550 women 75-89 years from 100 PCPs who provide care at an academic primary care or geriatrics practice in Boston, three community practices in the Boston metro area, or at an academic internal medicine or family practice in North Carolina. Patient participants will either receive the DA (intervention arm) or an educational pamphlet on home safety for older adults (control arm). The investigators chose to use PCPs as the unit of randomization rather than individual patients because they anticipate that some patients will share the DA with their PCPs. Once PCPs are exposed to the DA for one patient they could change their approach to screening which could lead to contamination of the control group making it more difficult to show an effect of the DA.

Aims:

The investigators will examine and evaluate the impact of providing information on benefits and risks of mammography screening to women aged 75 and older on:

1. receipt of screening;

2. intentions of being screened;

3. knowledge of the pros and cons of being screened;

4. decisional conflict around screening;

5. preferred decision-making role around mammography (active vs. passive/shared with physician);

6. documented discussions by PCPs of the risks and benefits of mammography screening in participants' notes.