Comparing GIS-Based Measures in Access to Mammography and Their Validity in Predicting Neighborhood Risk of Late-Stage Breast Cancer
Year: 2012
Type: article
Study design: Observational Study
Abstract: BACKGROUND: Assessing neighborhood environment in access to mammography remains a challenge when investigating its contextual effect on breast cancer-related outcomes. Studies using different Geographic Information Systems (GIS)-based measures reported inconsistent findings. METHODS: We compared GIS-based measures (travel time, service density, and a two-Step Floating Catchment Area method [2SFCA]) of access to FDA-accredited mammography facilities in terms of their Spearman correlation, agreement (Kappa) and spatial patterns. As an indicator of predictive validity, we examined their association with the odds of late-stage breast cancer using cancer registry data. RESULTS: The accessibility measures indicated considerable variation in correlation, Kappa and spatial pattern. Measures using shortest travel time (or average) and service density showed low correlations, no agreement, and different spatial patterns. Both types of measures showed low correlations and little agreement with the 2SFCA measures. Of all measures, only the two measures using 6-timezone-weighted 2SFCA method were associated with increased odds of late-stage breast cancer (quick-distance-decay: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.01-1.32; slow-distance-decay: OR = 1.19, 95% CI = 1.03-1.37) after controlling for demographics and neighborhood socioeconomic deprivation. CONCLUSIONS: Various GIS-based measures of access to mammography facilities exist and are not identical in principle and their association with late-stage breast cancer risk. Only the two measures using the 2SFCA method with 6-timezone weighting were associated with increased odds of late-stage breast cancer. These measures incorporate both travel barriers and service competition. Studies may observe different results depending on the measure of accessibility used.
Source: PLoS ONE
Authors: Min Lian, James Struthers, Mario Schootman
Institution: Washington University in St. Louis
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,382
Funders: University of Missouri, Alvin J. Siteman Cancer Center, Missouri Department of Health and Senior Services, National Institutes of Health, Centers for Disease Control and Prevention, Washington University School of Medicine in St. Louis, National Cancer Institute, National Center for Chronic Disease Prevention and Health Promotion
OpenAlex ID: W1995143216