Geospatial-socioeconomic Analysis of Patient Transportation-related Access Disparities to Radiation Treatment

Abstract

Unplanned interruption of radiotherapy (RT) predicts inferior treatment outcomes. Lack of adequate patient transportation is a preventable barrier to uninterrupted RT. In this study we examine the association of geospatial and socioeconomic factors with RT interruption due to patient transportation access shortfalls across a complete metropolitan region served by a single academic referral center. Data were collected for all patients treated with external beam RT from January 1, 2015 to December 31, 2017. Transportation-related RT interruption was defined as patient reported lack of transportation causing cancellation of at least 1 RT appointment. Patient predicted income (PPI) was modeled using 2017 US Census data for annual household income by patient residence census tract and categorized as low (<$34k), middle, or high (>$67k). Associations with transportation-related RT interruption rates were examined via Pearson’s Chi square and mapped by patient residence at the neighborhood (census tract) level. 82,773 total fractions (median 24, IQR 10-30) were delivered to 3729 patients with 7107 interruptions (8.6%) in 1928 patients (51.7%). 2022 (54.5 %) were Caucasian, 1577 (42.3%) were African American, and 120 (3.2%) were other races. Insurance status was defined as Commercial, Medicare, or Medicaid/Uninsured in 1794 (48.1%), 1503 (40.3%), and 432 (11.6%) patients respectively. Causes of interruption were identifiable in 6068 (85.5%) missed appointments, of which 226 (3.2%) were due to lack of transportation in 145 (3.9%) patients. There was significant elevation in RT interruptions due to transportation between Medicaid/Uninsured patients v. those with Commercial or Medicare insurance (8.3% v. 3.3% p = <0.0001; OR 2.66 [95%CI 1.80-3.93]), African American v. Caucasian patients (6.2% v 2.2% p = <0.0001; OR 2.97 [95%CI 2.08-4.23]), and low PPI v. high PPI patients (7.0% v 0.87% p = <0.0001; OR 8.64 [95%CI 4.47-16.70]). Increased rates of RT interruption due to patient transportation issues mapped to low income, majority African American neighborhoods (p = <0.0001). RT interruption due to lack of personal transportation disproportionately impacts patients who have Medicaid or no insurance, are African American, or have low PPI. Geospatial analysis identified hotspots in specific low income, majority African American neighborhoods. Further development of targeted interventions to improve transportation options for high-risk patients from identified neighborhood hotspots promises to decrease rates of RT interruption and to improve care quality and treatment outcomes for those patients.