False-positive mammograms don’t send patients fleeing from future screenings

Women who receive false-positive mammograms may be disconcerted, aggravated or otherwise put off by the experience, but they don’t subsequently abandon screening mammography guidelines en masse, according to a study running in the September edition of the Journal of the American College of Radiology.

Lara Hardesty, MD, and colleagues at the University of Colorado came to this conclusion after conducting a retrospective study of women over 40 who received 9,385 consecutive, nonbaseline screening mammograms at their institution’s health system in the 13-month period ending Dec. 31, 2013.

The team used linear regression to analyze differences in time between mammograms by prior recall status. They also considered the differences after adjusting for location of current mammogram—outpatient office (8,298 of the exams) versus mobile unit (1,087 exams)—and age.

Evaluating the association between compliance with screening guidelines and the recall status on prior mammogram, they compared the proportions of noncompliant women who were recalled from a prior mammogram.

The researchers’ key finding: Time between mammograms does not differ based on prior recall status to a statistically significant degree.

Thus, a false-positive mammogram “is not a significant deterrent to compliance with screening mammography guidelines for women who return for screening,” the authors write.

Other notable takeaway conclusions from the study included:

• Women who are not compliant with the American College of Radiology’s recommended screening interval are neither more nor less likely to have been recalled on their most recent prior mammogram (P = .398).
• Women who are not compliant with the U.S. Preventive Services Task Force’s recommended screening interval are neither more nor less likely to have been recalled on their most recent prior mammogram (P = .416).

Further, using linear regression to evaluate months between mammograms, Hardesty and team found that, after adjusting for age and location, being recalled on a prior mammogram was not associated with months between mammograms (P = .83).

Interestingly, the proportion of noncompliant women who were recalled on their prior mammogram was significantly higher at the outpatient office than on the mobile unit when noncompliance was assessed using either ACR (P = .0004) or USPSTF (P = .0032) screening guidelines.

A false-positive mammogram “is not a significant deterrent to compliance with screening mammography guidelines for women who return for screening,” the authors write. “The lack of altered behavior suggests that, although the stress and anxiety caused by being recalled for additional imaging is real, it is not of sufficient severity to dissuade women from returning for subsequent mammography in accordance with current screening recommendations.”

Hardesty et al. note as a limitation their evaluation of only women who presented for screening mammography, which yielded an incomplete picture of the screening-eligible population.

They cite as a strength their use of electronic medical records to assemble a complete retrospective cohort, which allowed them to evaluate an entire population that received screening mammograms for 13 consecutive months.