Date of Award


Document Type

Open Access Thesis


Epidemiology and Biostatistics


The Norman J. Arnold School of Public Health

First Advisor

Jan Eberth


Little information is known on what demographic, behavioral, and procedural factors influence the number of polyps found during a colonoscopy screening for colorectal cancer (CRC). The main objective of this study is to describe the polyp detection rate (PDR), number of polyps removed, and predictors of polyp count overall and for high-risk polyps among uninsured patients undergoing colonoscopy in the Colorectal Cancer Prevention Network (CCPN) program of South Carolina. We performed a secondary data analysis on CCPN data for colonoscopies performed between May 2014 and May 2017. We assessed the association of polyp count with the following variables: age, race, gender, smoking status, alcohol use, BMI, family history of CRC, education status, NSAID use, physical activity, rural/urban residence, bowel preparation quality, and time of procedure. We hypothesized that since these variables have been shown to influence the risk of colonic polyps they will also influence the number of all polyps and number of high-risk polyps detected during colonoscopy. Total PDR within this study was 61.82%. Respective mean, median, and max number of polyps removed were 1.65, 1.00, and 15 for all polyps and 0.31, 0, and 13 for high-risk polyps. Multivariable analyses found male gender, current and former smokers, moderate alcohol use, family history of CRC, obesity, and never using NSAIDS to be positively associated with total number of polyps detected; rural residence was negatively associated with number of total polyps. Males, current smokers, and using NSAIDS 1-3 days/week, occasionally, or never were found to have a higher number of high-risk polyps. A later procedure time resulted in a lower number of high-risk polyps than the earliest procedure times. This study demonstrates the effects that demographic, behavioral, and procedural influencers have on polyp detection and the number of polyps detected during a colonoscopy procedure. Based on these relationships, our findings may help to identify individuals who are at risk for a high number of polyps, which could possibly lead to better detection of polyps during their colonoscopy procedure.


© 2018, Lauren Hill

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