Date of Graduation

2014

Document Type

Dissertation

Degree Type

PhD

College

School of Pharmacy

Department

Pharmaceutical Sciences

Committee Chair

Suresh Madhavan

Committee Co-Chair

Sobha Kurian

Committee Member

Xiaoyun Pan

Committee Member

Michael Regier

Committee Member

Usha Sambamoorthi

Abstract

West Virginia (WV) which is one of the most rural states in the nation, had the highest colorectal cancer (CRC) mortality rate in United States (US) in 2009. There is a paucity of epidemiologic studies that have decrypt the reasons for this high CRC mortality, or have systematically examined the burden of, and disparities among the population of elderly with CRC from a rural settings such as from WV. This series of retrospective cohort studies was conducted to examine the receipt of CRC treatment and the associated survivorship, comorbidity burden, and healthcare expenditures among Medicare beneficiaries with CRC identified from the West Virginia Cancer Registry Medicare linked (WVCR Medicare); and to compare them with national estimated derived from the Surveillance, Epidemiology, and End Results Medicare (SEER Medicare) data. These studies examined CRC treatment patterns, receipt of minimally appropriate CRC treatment (MACT), healthcare expenditures in the initial phase of care, and CRC specific and all cause mortality in the 36 month period following the CRC diagnosis in the two study cohorts. The associations of specific pre-existing chronic conditions with the treatment receipt, healthcare expenditures, and survivorship was also explored. In the first study, it was observed that the characteristics of the two study cohorts were significantly different with those from WVCR Medicare having higher comorbidity burden, and living in non-metro areas. Although a higher proportion of beneficiaries from WVCR Medicare were diagnosed in the earlier stages of CRC (when it can still be treated effectively) as compared to their national counterparts from SEER Medicare, they exhibited CRC poor survivorship. This poor survivorship was possibly due to the lower likelihood of beneficiaries from WVCR Medicare of receiving MACT as compared to the beneficiaries identified from SEER Medicare; as observed in the study results. In study two, which studied the pre-existing chronic conditions among the WVCR Medicare beneficiaries with CRC, no substantial evidence was found to conclude that beneficiaries with CRC and comorbidities were treated less aggressively as compared to those without comorbidities; as reported by some other studies. Only a few conditions were found to be negatively associated with CRC specific mortality, but almost all the chronic conditions were negatively associated with all--cause mortality among beneficiaries from WVCR Medicare. The results from study three showed that after adjusting for the regional variation in cost-of-living across the different counties included in the study, the difference in total healthcare expenditures between the beneficiaries with CRC from a rural area such as in WV and their national counterparts can be believed to be mainly driven due to the differential treatment receipt and the high comorbidity burden. These studies can serve as a good case-studies to elucidate the receipt of CRC treatment and the associated health outcomes in a CRC population that is aging, is sicker, belongs to lower socio-economic status, and is from a rural setting. Future research is necessary to determine if similar associations are observed in other rural areas in the nation, and also to better understand the implementation of and receipt of guideline recommended CRC care and the associated health outcomes among beneficiaries with CRC from such areas.

Download

Share

COinS