Physician Breast Cancer Screening Recommendations Following Guideline Changes: Results of a National Survey

Different professional societies and organizations continue to disagree over the optimal time to initiate and discontinue breast cancer screening mammography and the optimal screening interval. In October 2015, the American Cancer Society (ACS) revised its guidelines, encouraging personalized screening decisions for women ages 40 to 44 years followed by annual screening starting at age 45 years and biennial screening for women 55 years or older.¹ The US Preventive Services Task Force (USPSTF) reissued its recommendations in January 2016 recommending personalized screening decisions for women ages 40 to 49 years followed by biennial mammograms for women ages 50 to 74 years.² The American Congress of Obstetricians and Gynecologists (ACOG) recommends yearly mammograms for women 40 years or older.³ With physician recommendations the most important determinant for patients obtaining screening,⁴ we investigated physician recommendations in light of recent guideline changes in a national sample.

Methods

The Breast Cancer Social Networks study (CanSNET) is a national survey of primary care physicians (PCPs), including internal medicine (IM) and family medicine/general practice (FM/GP) physicians, and gynecologists about their breast cancer screening practices. Mailed surveys were sent to 2000 physicians randomly sampled from the American Medical Association Physician Masterfile from May to September 2016. Physicians were eligible if they reported providing primary care or general gynecologic care to women 40 years or older. The survey asked whether they typically recommended routine screening mammograms to women with no family history of breast cancer and no prior breast issues in different age groups and at what intervals; it did not ask explicitly about whether physicians engaged in personalized decision making. Physicians also indicated which organization’s screening guidelines they most trusted.

We conducted bivariate analyses to assess the associations between screening recommendations and (1) physician specialty and (2) organizational trust. We focused on women ages 40 to 44 years, 45 to 49 years, and 75 years or older, where guidelines are discordant. The Johns Hopkins University institutional review board approved this study.

Results

After excluding ineligible participants, the adjusted response rate was 52.3% (871 of 1665). The average age of physicians was 52.9 years, with most (54.6%) being male and non-Hispanic white (70.6%). Family medicine/general practice physicians comprised 44.2% of the sample, 29.7% were IM physicians, and 26.1% were gynecologists. More than half of physicians had over 20 years of experience in practice and were employed in physician-owned practices. Nonresponders were more likely male and IM physicians.

Overall, 81% of physicians recommended screening to women ages 40 to 44 years, 88% to women ages 45 to 49 years, and 67% for women 75 years or older. Compared with IM and FM/GP physicians, gynecologists were more likely to recommend screening for women of all age groups (P < .001) (Figure 1). Among clinicians who recommend screening, most recommend annual examinations: 62.9% for women ages 40 to 44 years, 66.7% for women ages 45 to 49 years, and 52.3% for women 75 years or older.

Figure 1. Proportion of Physicians by Specialty Who Recommend Breast Cancer Screening to Women of Different Age Groups.

FM indicates family medicine; GP, general practitioner; IM, internal medicine.

^aDenotes statistically significant (P< .05) differences between specialties.

More than a quarter of physicians (26.0%) reported trusting ACOG guidelines most; 23.8%, ACS guidelines; and 22.9%, USPSTF guidelines. Physicians who trusted ACS and ACOG guidelines were significantly more likely to recommend screening younger women compared with those who trusted USPSTF guidelines (ACS guidelines, 86.5%; ACOG guidelines, 92.9%; USPSTF guidelines, 60.8% for women ages 40–44 years; and ACS guidelines, 94.7%; ACOG guidelines, 95.6%; USPSTF guidelines 72.4% for women ages 45–49 years) (Figure 2). This pattern was similar among women 75 years or older (ACS guidelines, 73.4%; ACOG guidelines, 78.3%; USPSTF guidelines, 44.2%) (Figure 2).

Figure 2. Proportion of Physicians Who Recommend Breast Cancer Screening Categorized by Which Guidelines Physicians Report Trusting the Most.

ACOG, American Congress of Obstetricians and Gynecologists; ACS, American Cancer Society; USPSTF, US Preventive Services Task Force. ^aDenotes statistically significant (P< .05) differences based on most trusted organizational guideline.

Discussion

In a nationally representative sample of physicians, we found that PCPs and gynecologists largely recommended screening to women 40 years or older. Our findings are largely consistent with a 2014 survey of PCPs from 4 clinical networks where similar proportions of physicians recommended screening with higher rates noted among gynecologists.⁵ We also found sharp differences in recommendations based on which guidelines physicians trusted most, which may suggest that current practices reflect both varying adherence to guidelines as well as differences in which guidelines are trusted. The results provide an important benchmark as guidelines continue evolving and underscore the need to delineate barriers and facilitators to implementing guidelines in clinical practice.