EP629 - Establishing a Baseline Adenoma Detection Rate at St. John’s Episcopal Hospital: A Retrospective Analysis

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Purpose/Background: Colorectal cancer (CRC) is one of the main causes of cancer death around the world. Screening colonoscopy can reduce the incidence of CRC through the detection and removal of adenomatous polyps. One key quality measure is the Adenoma Detection Rate (ADR); a higher ADR reflects a lower risk for CRC. This study aimed to establish a benchmark ADR at St. John's Episcopal Hospital for quality improvement.

Methods/Interventions: In this retrospective review, the researchers reviewed the medical records of all screening colonoscopies conducted in the period between August 2023 and August 2024. The study included patients aged 18 years and above undergoing screening colonoscopies and excluded diagnostic colonoscopies. Demographics, colonoscopy findings, location of lesions, and pathology reports were retrieved from electronic medical records. All procedures were performed by three board-certified gastroenterologists. The ADR was defined as the number of colonoscopies in which at least one adenoma was detected. Descriptive statistics summarized the findings. SPSS software was used to analyze the data.

Results/Outcomes: Overall, there were 322 screening colonoscopies during the study period. The average age of the patients was 60 years (SD: 9.1); the youngest was 35. Males consisted of 39.1% (126/322) of the cohort and females, 60.9% (196/322). Overall ADR was 27.0%. Male ADR was 30.95%, while female ADR was 24.48%. 92.2% of the colonoscopies were completed, the rest were not due to poor bowel preparation. The distribution of polyps was as follows: 39.4% of patients had polyps, out of which 38% were in the ascending colon, followed by the sigmoid colon (34%), descending colon (19%), and rectum (21.5%). The histopathological examinations showed that the main type was tubular adenomas, with 57.4%, followed by hyperplastic polyps, 30.7%. Other findings included tubulovillous 2%, serrated 3.9%, and sessile polyps 3.1%. Malignancy was found in 0.9%, showing that there was a low but present risk for CRC.

Conclusion/Discussion: The ADR baseline at St. John's Episcopal Hospital is 27.0%, within the limits but lower compared to institutions with higher performances. Studies, such as those by Corley et al. (2014) and Wong et al. (2019), have established that ADRs greater than 30% yield better CRC prevention. In this study, the male ADR was also observed to be higher than that of females, a trend consistent with the literature where generally, male patients are at a higher risk of developing adenomas. The mean age was 60 years, and the Lilliefors test value of 0.02 reflects that the distribution was skewed towards the older age and not even. With this older population, one might expect a higher ADR; however, there could be influences for the lower rate. Factors that will influence this include the quality of poor bowel preparation, which may obscure visibility and thereby identify fewer polyps and ethnic and genetic factors related to adenoma prevalence in the population that the hospital serves. The level of education and engagement of the patients will also affect their ability to prepare adequately and follow through with screening recommendations. These findings point to various areas of improvement that include technique optimization, enhancement of patient education and engagement in improving bowel preparation, and further consideration of demographic factors that may affect ADR outcomes. It sets a very important base ADR that will be used to monitor and improve colonoscopy performance in the institution.