Onega T, Lee CI, Benkeser D, Alford-Teaster J, Haas JS, Tosteson AN, Hill D, Shi X, Henderson LM, Hubbard RA. J Am Coll Radiol. 2016 Jun;13(6):611-9. doi: 10.1016/j.jacr.2016.01.022. Epub 2016 Mar 22.
Mammography, unlike MRI, is relatively geographically accessible. Additional travel time is often required to access breast MRI. However, the amount of additional travel time and whether it varies on the basis of sociodemographic or breast cancer risk factors is unknown.
MATERIALS AND METHODS:
The investigators examined screening mammography and MRI between 2005 and 2012 in the Breast Cancer Surveillance Consortium by (1) travel time to the closest and actual mammography facility used and the difference between the two, (2) women’s breast cancer risk factors, and (3) sociodemographic characteristics. Logistic regression was used to examine the odds of traveling farther than the closest facility in relation to women’s characteristics.
Among 821,683 screening mammographic examinations, 76.6% occurred at the closest facility, compared with 51.9% of screening MRI studies (n = 3,687). The median differential travel time among women not using the closest facility for mammography was 14 min (interquartile range, 8-25 min) versus 20 min (interquartile range, 11-40 min) for breast MRI. Differential travel time for both imaging modalities did not vary notably by breast cancer risk factors but was significantly longer for nonurban residents. For non-Hispanic black compared with non-Hispanic white women, the adjusted odds of traveling farther than the closest facility were 9% lower for mammography (odds ratio, 0.91; 95% confidence interval, 0.87-0.95) but more than two times higher for MRI (odds ratio, 2.64; 95% confidence interval, 1.36-5.13).
Breast cancer risk factors were not related to excess travel time for screening MRI, but sociodemographic factors were, suggesting the possibility that geographic distribution of advanced imaging may exacerbated disparities for some vulnerable populations.