The Effect of Patient Travel Distance on Breast Cancer Treatment and Survival - Abstract
The distance patients need to travel to care facilities is a recognized barrier to accessing heath
care. However, little is known about the role of travel burden on patient choice of treatment strategy,
adherence to that treatment strategy, and, ultimately, treatment outcomes. Women diagnosed with
early stage breast cancer have two guideline-supported treatment options: 1) mastectomy and 2)
breast-conserving surgery (BCS) followed by radiation therapy (RT)1-3. While overall survival between
the two choices is equivalent, BCS+RT is associated with reduced complications and costs4 and
superior quality of life relative to mastectomy5. Distance, however, may play a significant role in patient
decision-making, since RT requires daily travel to radiation facilities for several weeks at a time. The
combination of two clinically comparable treatment options with different travel implications provides a
unique opportunity to evaluate the impact of travel distance on care decisions and outcomes. I will use
the linked Surveillance, Epidemiology and End Results (SEER)-Medicare 2004-2014 data, which
covers 28% of the total U.S. population and contains detailed information on patient demographics and
place of residence, tumor characteristics and disease severity, location of treatment received, and
patient survival. Using the linked claims data will allow me to assess distance traveled, minimum
distance required, whether a patient actually received RT following BCS20, whether the treatment was
completed, and over how long a period. The 10-year time period allows me to evaluate changes in the
availability of radiation facilities. Under Aim 1, I will quantify the burden of travel and how it has changed
over time among breast cancer patients in the Medicare population and identify patient demographic
factors (age, race/ethnicity, marital status, income, rurality) associated with greater travel burden.
Under Aim 2, I will evaluate the association between travel distance and 1) patient choice of surgical
treatment (mastectomy or BCS) and 2) adherence to a complete course of RT among BCS patients.
Under Aim 3, I will exploit the variation in the availability of radiation facilities over time caused by
facility opening or closure to determine how patients in a given geographic area respond to changes in
access to radiation facilities. I will also estimate the patient survival hazard ratio associated with living in
a county with versus without a radiation facility. This research will contribute to the larger discussion
surrounding the importance of efficient resource allocation, incentivizing practice in underserved
locations, the impact of consolidating health care markets, and improving access to needed services for
rural and remote populations.
