By Shelley Chen
Previous studies reported that patients who live farther from cancer centers do not necessarily experience delayed cancer detection and shortened survival. However, the results are biased because of the incomplete observation of patient survival, which cannot be properly accounted for with the multivariable regression model. In this thesis, I isolated the effect of the breast cancer patient’s distance to a comprehensive cancer center on the stage of diagnosis and survival using the Cox Proportional Hazards model. I linked data from the Kentucky Surveillance, Epidemiology, and End Results 18, the Kentucky Life Tables, and the Kentucky Area Health Resource Files and identified 37654 patients diagnosed with breast cancer. I estimated the effect of distance on marginal probability of cancer mortality, controlling for non-cancer related death, socioeconomic status, and demographic factors in patients. After controlling for covariates, travel distance between the patient and the nearest comprehensive cancer center was statistically significantly on the breast cancer mortality probability, but not on the stage of diagnosis. In the Kentucky population, patients who were located farther from comprehensive cancer centers experience an increased marginal probability of mortality (proportional hazard = 1.004; 95% CI: [1.000502 1.007311]). The linkage of SEER 18 and AHRF data provided more comprehensive information on the socioeconomic risk factors of cancer mortality than past study datasets. For the stage of diagnosis, a low physician to population ratio and high county-level Medicaid coverage were associated with more advanced stages of diagnosis. In turn, a more advanced stage of diagnosis, lower physician to population ratio, and identification as African American increased the marginal probabilities of mortality.
Advisor: Charles Becker, Kent Kimbrough | JEL Codes: I1, I13, I14 | Tagged: B