Abstract C06: Travel burden to breast biopsy facilities by race and disadvantage in Chicago
Authors: Khan Jenna A. , Rauscher Garth 
Published: May 2015

Purpose: The purpose of this analysis is to explore travel burden to biopsy facilities incurred by breast cancer patients.

Methods: We geocoded patient residence and biopsy facility addresses from Breast Cancer Care in Chicago, a population-based study of breast cancer patients diagnosed from 2005-2008 (n=989). Street network based drive times from patient residence to the facility where the patient received biopsy services were calculated using ArcGIS. Public transportation times were obtained using Google Transit ‘best route’ and set to arrive at the facility by 11:00am on a Thursday. The percentage of households owning a vehicle for each patient's census tract (US Census 2010) was used to calculate a weighted travel time from both driving and public transportation times. An additional ‘assigned’ travel time was set as the drive time when tract-level vehicle ownership was ≥50% and set as public transportation time when tract-level vehicle ownership was &lt;50%. Kruskal Wallis and Wilcoxon Rank Sum tests were used to examine the differences between travel times by census tract level disadvantage (&lt;1 SD below the mean, within 1 SD of the mean, &gt;1 SD above the mean) and affluence (&lt;1 SD below the mean, within 1 SD of the mean, &gt;1 SD above the mean), race/ethnicity (nH black, Hispanic, nH white), highest education received (&lt;high school, high school, &gt;high school), annual household income (&lt;30k, 30-75k, &gt;75k), insurance status (none, public, private) and region of the city (south side vs. north side).

Results: Patient residence and biopsy facility locations were available for 890 patients. Average weighted travel time was 17 minutes (range 0.5 to 85) and average assigned travel time was 11 minutes (range 0.3 to 74), whereas average drive time alone was 9 minutes (range 0.3 to 58) and average public transportation time alone was 45 minutes (range 3 to 190). Non-Hispanic (nH) black and Hispanic women had longer travel times than nH white women for all types of travel time (all p&lt;0.01). Women living in census tracts of higher disadvantage and lower affluence also had longer travel times than their counterparts for each type of travel time (all p&lt;0.001). Women with private insurance had shorter travel times that women with public insurance or women without insurance using the weighted travel time (p=0.01). Women living on the south side of Chicago had longer travel times that women living on the north side for all types of travel time (all p&lt;0.0001).

Conclusions: Longer travel times to biopsy services could potentially serve as a barrier causing delays in diagnoses. Prior analysis among this study population found no meaningful differences in travel time to breast cancer care facilities using drive time alone. The addition of public transportation times provides a more realistic estimate of travel burden among women in Chicago. We found that women of greater disadvantage had longer travel times to their biopsy facilities. We also found longer travel times among women living on the south side of Chicago, which is where the most predominately nH black and socioeconomically disadvantaged neighborhoods are located. Greater travel burden incurred by disadvantaged women may be contributing to Chicago's racial disparity in breast cancer stage at diagnosis. Future analyses will explore how travel burden to breast cancer care facilities relates to breast cancer outcomes.

Citation Format: Jenna A. Khan, Garth Rauscher. Travel burden to breast biopsy facilities by race and disadvantage in Chicago. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C06. doi:10.1158/1538-7755.DISP13-C06