Effect of false-positive mammograms on return for subsequent screening mammography.

There has been concern that false-positive mammograms may deter women from future screening mammograms. We sought to determine whether false-positive mammograms affected follow-up for rescreening. We studied a cohort of 41,844 women in the Vermont Mammography Registry. We measured the proportion of women returning for the next screening mammogram for 30 months following an initial screening mammogram, and compared rates of follow-up screening at 18 and 30 months in women with false-positive and true-negative initial mammograms. We adjusted for potential confounders using multivariable logistic regression models. Of the 2469 women aged 50 years or older with false-positive mammograms, 67.2% (n = 1660) returned at 18 months for rescreening, compared with 63.9% (16,948/26,521) of the women with true-negative mammograms (P = 0.001). Similarly, 86.8% (2143/2469) of the women with false-positive mammograms returned at 30 months for rescreening, compared with 84.7% (22,466/26,521) of the women with true-negative mammograms (P = 0.005). After adjusting for age, use of hormone replacement therapy, prior mammography, prior false-positive mammography, and education, women with false-positive mammograms were more likely to return at 18 months (odds ratio [OR] = 1.40; 95% confidence interval [CI]: 1.30 to 1.51) and at 30 months (OR = 1.30; 95% CI: 1.18 to 1.44). Despite previous concerns, false-positive screening mammograms did not discourage women from returning for subsequent screening mammography. However, other deleterious effects of false-positive results still warrant improvements in the accuracy of breast cancer screening.