The Effect of Payer Status on Survival of Patients With Prostate Cancer

Abstract
Disparities in access to care and proper treatment can have significant implications in patient survival outcome and mortality. This retrospective study of prostate cancer patients from the National Cancer Database (NCDB) between the years 2004 and 2014 and follow-up to the end of 2015 analyzed such effects that variation in payer status might have on outcome. This study used the data of 696,321 diagnosed prostate cancer patients from the NCDB for the years 2004 to 2014 and follow-up to the end of 2015 to analyze the effect that payer status would have on prostate cancer survival. Multivariable cox regression was used to study the hazard ratios (HRs) of payer status and other variables along with the Charlson Comorbidity Index to analyze their associated increased risk of death. Statistical software SAS 9.4 for Windows was used to analyze the overall survival (OS) of patients on different insurance plans along with variations in prostate-specific antigen (PSA) levels and treatment type. When looking at OS, those with private insurance had the greatest overall survivability while those on Medicare were the only ones who reached the median OS. In contrast to those who had private insurance, those who had Medicare, the uninsured, and those with Medicaid demonstrated significantly greater risks of death at 43%, 58%, and 69% increased risk of death, respectively. In addition to payer status, other variables were also significant predictors of OS, including demographic factors (age, race), comorbidities, socioeconomic status (income, education), distance traveled to facility, type of facility, treatment delay, treatment modality, PSA levels at diagnosis, and cancer stage at diagnosis. Payer status is intricately linked to a number of other variables that might affect survival. Even after adjustment for a number of these factors, insurance status was shown to have a significant effect on prostate cancer survivorship. In contrast to those who had private insurance, those who had Medicare, the uninsured, and those with Medicaid demonstrated significantly greater risks of death at 43%, 58%, and 69% increased risk of death, respectively. Studies have suggested that those without insurance or on Medicaid are less likely to undergo screening and have worse health-related quality of life, while those on Medicare may be deterred from continuing treatment due to high out-of-pocket costs. However, the complete mechanism behind the improved survivorship of those on private insurance is unclear. The effect of payer status on quality of life may be an interest that needs to be further studied. Further research will be required to provide definite reasons for these observations and mediation analysis of other factors could prove to be valuable.