Date of Award

Summer 2022

Document Type

Open Access Thesis


Epidemiology and Biostatistics

First Advisor

Michael D Wirth


Colorectal cancer (CRC) is the third most common cancer and the second most among cancer deaths both in the US and globally. Early Onset Colorectal Cancer (EOCRC), occurring between the ages of 20 and 49, has continued to rise over the past decades. Several studies have reported a persistent increase in EOCRC incidence and mortality, especially in rural areas as compared to urban areas, despite decreases in rates for people over the age of 50 years. Increase in EOCRC may have played a role in lowering the age of screening recommendation to 45-49 age group. The objective of this study was to examine the association between rural-urban status and survival in an EOCRC population. The twofold objectives were, 1) to determine the rural-urban differences in 1-, 3- and 5-year survival among individuals with EOCRC and, 2) to evaluate the ruralurban differences in EOCRC survival by gender, age, race, ethnicity status, and payer types (any Medicaid, insured/no specifics, uninsured and unknown groups). Descriptive statistics for the sample were calculated and compared by rural-urban status using chisquare tests. Kaplan-Meier survival curves were constructed to examine rural-urban differences in survival among EOCRC patients. Adjusting for various characteristics, multivariable extended cox proportional hazards analyses were used to estimate hazards ratios and were reported as estimates and 95% confidence intervals. Among the included 65,716 EOCRC patients, rural patients had lower 5-year survival from EOCRC as compared to urban patients (69% vs. 71%, P

Available for download on Thursday, October 05, 2023

Included in

Epidemiology Commons