Adherence to colorectal cancer (CRC) re-screening is essential to maximize screening effectiveness. This study assessed adherence to a multi-target stool DNA (mt-sDNA) test among previous users in the USA across different payer types. Data from Exact Sciences Laboratories LLC (01/01/2023–12/31/2023) were used. Insured patients (45–85 years) who were shipped an mt-sDNA test during the data coverage period and had previously completed mt-sDNA screening with a negative result ≥ 2.5 years prior were included. Mt-sDNA re-screening adherence rate and mean time to test return were compared across payer types, and their associations with patient characteristics were assessed using multivariable regression models. Of 793,567 patients (50–75 years: 89.0

OBJECTIVES:To describe member adherence to a mail-based, health insurer-sponsored gap closure program for colorectal cancer (CRC) screening using multi-target stool DNA (mt-sDNA; Cologuard®) tests. METHODS:Combined patient data from Exact Sciences Laboratories LLC and data from mass-mailed mt-sDNA orders placed by a large Medicare Advantage Insurance Plan were analyzed (03/01/2023-06/30/2023). Adherence and time to test return were the primary and secondary outcomes, respectively. Their association with patient characteristics was evaluated using multivariable regression. RESULTS:Among the 3201 member-patients included (86.6% aged 65-75 years; 58.7% female), adherence rate was 49.4%, and mean time to test return was 25.5 days. After multivariable adjustment, the odds of test return were significantly higher among 65- to 75-year-olds (odds ratio [OR] = 1.59 relative to 45- to 64-year-olds), those living in small towns (OR = 1.43 relative to metropolitan-located individuals), and with digital outreach via both SMS and email (OR = 4.31 relative to no digital outreach). Time to test return was shorter in 65- to 75-year-olds than in 45- to 64-year-olds and was not associated with other patient characteristics. CONCLUSIONS:Mass-mailed mt-sDNA tests for CRC screening were associated with an overall adherence rate of about 50% in this Medicare Advantage population, with higher likelihood of test return among patients receiving digital outreach.

e15633 Background: Colorectal cancer (CRC) is the fourth most diagnosed cancer, as well as the second leading cause of cancer death in the United States – with an estimated 152,810 diagnoses and 53,010 fatal cases in 2024. Regular screening and early detection can reduce CRC incidence and improve overall survival; however, recent national survey data (2021) demonstrate that only 59% of the US screen-eligible population (≥ age 45) is up to date. Home-based, non-invasive CRC screening test options, such as the multi-target stool DNA (mt-sDNA) test, have the potential to improve patient outcomes and overcome CRC screening adherence barriers at multiple levels. Given that the recommended interval for mt-sDNA is three years, a better understanding of use in repeat users is warranted. We evaluated the effective rescreen rate of previous mt-sDNA test users. Methods: In this retrospective cohort study, we included patients between the ages of 45 and 75 years who were shipped an mt-sDNA test kit between January 1st – December 31st, 2023, and had previously completed mt-sDNA screening with a negative result > 2.5 years prior. Our primary variable of interest was mt-sDNA completion rate on repeat testing, defined as kit receipt with a valid result within 120 days of the shipment date. Regression analysis was performed to determine baseline characteristics associated with repeat test completion rate. Results: During the analysis period, a total of 481,748 patients who met the inclusion criteria received an mt-sDNA kit. The majority of the cohort was female (61.4%) and between the ages of 65-75 years (50.9%). Overall repeat test completion rate was 83.6%, with the average time to kit return being 18.9 days. Completion rates were similar between males (83.8%) and females (83.6%), and patients receiving included navigation support via mobile phones demonstrated the shortest average time to kit return (18.7 days). Completion rates increased concordantly with patient age: 81.6%, (45-49 years), 82.2% (50-64 years), and 85% (65-75 years). For first-time rescreen participants (2nd lifetime mt-sDNA test), the completion rate was 83.1%. For second-time rescreen participants (3rd lifetime mt-sDNA test), the completion rate was even higher at 93.6%. Logistic regression analyses revealed that patients re-screening for a second-time were three times more likely to return the mt-sDNA kit for CRC screening (OR = 3.118; p < 0.001). Conclusions: Data from this large, retrospective cohort study revealed that repeat CRC screening with the mt-sDNA test is associated with high adherence to triennial follow-up among participants. suggesting a high-level of perceived patient confidence in repeat performance of the mt-sDNA test. These novel data provide relevant insights regarding strong patient willingness to continue with home-based, non-invasive mt-sDNA testing over multiple cycles of average-risk CRC screening.

e15632 Background: In 2024, colorectal cancer (CRC) is estimated to be the fourth most diagnosed cancer, as well as the second leading cause of cancer death in the United States. While adherence to regular CRC screening has been suboptimal in the general population, this holds to be especially true in populations that are medically underserved. Non-invasive tests, such as the guideline recommended multi-target stool DNA (mt-sDNA) test, offer a more accessible option to increase screening participation in difficult to reach populations. Herein, we evaluated adherence to CRC screening in a cohort of prisoners who received the mt-sDNA test at a Nebraska Department of Corrections facility in Nebraska. Methods: This was a retrospective cohort study in a small prison population. Participants included both males and females between the ages of 45 and 75 years who underwent CRC screening evaluation at the prison’s medical center between June 1st – December 31st, 2023 and were offered multiple CRC screening options, including the mt-sDNA test. No inducements were provided for completion of the mt-sDNA test. Baseline demographics were collected for cohort description. The primary variable of interest was mt-sDNA test return rate (adherence), defined as completion of the mt-sDNA test within 60 days of kit receipt. We also evaluated mt-sDNA test results in secondary analyses. Results: Once inclusion criteria were applied, the resulting analysis cohort included 129 patients who were first time mt-sDNA screeners. The cohort was largely male (96.9%) and between the ages of 50-64 years (78.3%). Overall mt-sDNA test adherence was 95.3%, with the average time to test completion being 20 days. No significant difference was seen in test completion among males and females (95.2% vs 100%, respectively). Completion rates increased with patient age, at 90.9% (45-49 years), 95% (50-64 years), and 100% (65-75 years). The shortest time to completion in the population was observed amongst patients who were females (18.8 days), and those between the ages of 45-49 years (17.1 days). Negative and positive mt-sDNA test results were observed in 82.9% and 17.1% of the cohort, respectively. Conclusions: CRC screening with the mt-sDNA test in this single-center study of incarcerated participants yielded exceptionally high adherence rates within 60 days of kit receipt. Assessment of follow up colonoscopy rates for test-positive participants is ongoing. While based on a relatively small sample size in this initial study, the mt-sDNA test exhibited favorable completion rates in a difficult to reach population, supporting further efforts to characterize patient, provider, and system-level benefits that may be obtained through broader adoption of this highly accessible screening approach in this challenging healthcare setting.

Transportation agencies commonly identify and mitigate crash hot spots. Using a full roadway (i.e., including both intersections and segments) crash analysis is beneficial, but the results may be skewed towards locations with high intersection crashes. The purpose of this paper is to demonstrate the use of a combination of two unique, yet complementary crash hot spot analyses, one for intersections and one for roadway segments. The combination of the two allow for an in-depth analysis of causes associated with specific roadway conditions to identify locations that are experiencing more injury-causing crashes than predicted. The crashes on the state route network are separated into one of the two analyses; crashes within the influence area of major intersections become part of the intersection analysis and all other crashes become part of the segment-only analysis. Due to the separation between intersection- and segment-related crashes, safety concerns can be brought to light that might otherwise go unnoticed in a full network analysis. For example, crashes related to driveways or excessive queuing found in the segment analysis indicate a potential need for access management countermeasures. In addition, locations with both adjacent segment and intersection hot spots can be pinpointed as places for more in-depth analysis of the contributing circumstances surrounding the crashes at these locations. Agencies that use an intersection analysis and a segment analysis together to identify crash hot spots can benefit from an increased accuracy of hot spot locations. Furthermore, the approach to mitigating safety concerns can become clearer if hot spots are separated into intersections and segments.

One common challenge of modeling intersection related crash data is the high proportion of sites with zero crashes. Extensive research has been done on appropriate methods to handle excess zeroes. There is some reluctance to use zero-inflated models in the traffic safety literature. The primary purpose of this paper is to evaluate zero-inflated models to determine if they are a suitable method for modeling crash counts. An appropriate approach to model selection is to choose the model that best accomplishes research objectives rather than attempting to discover the true underlying data generating process. Thus using zero-inflated models is warranted when they outperform other models relative to research objectives. In addition, using zero-inflated models does not assume sites are in an inherently safe or unsafe state, and should not be summarily dismissed on the basis of disagreement with the hypothesized underlying data generating process. Secondarily, we compare implementations of zero-inflated Poisson, zero-inflated negative binomial, and negative binomial-Lindley Bayesian hierarchical models using intersection related crash data for the state of Utah from 2014 to 2018. We specifically compare the quality of fit as determined by a Bayesian χ2 test for goodness-of-fit and their relative predictive accuracy. The zero-inflated negative binomial performs best overall. We conclude that there are cases where zero-inflated models perform as well or better than other comparable models and may be considered as a viable option to model crash counts.