It has been several years since the new 2020 USMSTF guidelines were released. Here, we have shown that despite the time that has lapsed since 2020, premature rates of surveillance colonoscopy after detection of HPs and LRAs remain high - with an 82% and 64% rate of premature colonoscopy, respectively. In contrast, it was notable that patients with HRAs had a late colonoscopy, with a rate of 31% (33/106). These data raise a number of important points.

Adherence with USMSTF surveillance guidelines has been reported to be low after screening colonoscopy for at least the last decade [1, 10, 21]. In one study, 36% of physician recommendations were non-adherent to the 2012 guidelines [5]. In another study, non-adherence rates were 28% after normal colonoscopies, 52% after identification of HPs, 45% after finding LRAs, and 49% after HRAs [22]. It has been postulated that endoscopists were slow to adopt or disagreed with the new guidelines [1, 21]. The biggest change to the new guidelines was an increase in the interval for repeat colonoscopy in patients with 1–2 small adenomas (from 5 to 10 years to 7–10 years). Other changes included increasing the interval for patients with 3–4 small adenomas from 3 to a range of 3–5 years and new specific recommendations for the timing of second surveillance colonoscopies based on both baseline and first surveillance findings for tubular adenomas [8, 23]. When looking into physician-recommended interval recommendations after having their first surveillance we saw that the adherence rate was 50.2% between index and 1 st surveillance, and 35.7% between 1 st and 2nd surveillance colonoscopies in tubular adenomas. This could be due to endoscopists not being aware that there are interval recommendations for baseline 1 st surveillance findings, or it could also be due to the complexity of looking back at the baseline screening colonoscopy findings. Interestingly, during the time frame after publication of the 2012 USMSTF guidelines, more than half of gastroenterologists stated that for a single small adenoma, they would recommend an interval of 3 years, whereas the new recommendations are for repeat colonoscopy after at least 5 years [9, 24]. For higher-risk adenomas, gastroenterologists have historically recommended frequent follow-up (3 years or sooner in a 2004 national survey) [6]. These persistent discrepancies between guideline recommendations and real-world practice underscore the need to better understand factors driving premature surveillance.

Our findings are in part consistent with previous data and in addition add additional information to the field. In a study that examined compliance with the 2020 guidelines after an initial screening colonoscopy, adherence to the guidelines was 49% for all polyps, ranging from 8% for LRAs to 88% for HRAs, 89% for HPs, to 63% for SSPs [10]. While the overall compliance rate in this study and the current study was similar, the rate for HP and HRA in our study was notably different. We observed higher rates of premature surveillance in HPs and delayed surveillance in HRAs. Notably, the prior study did not examine patterns of premature versus delayed surveillance or evaluate other patient- and procedure-level factors associated with these outcomes. In addition, that analysis was performed approximately two years after guideline release, whereas our study assessed adherence over a longer post-implementation period, allowing evaluation of temporal trends in real-world practice. It has been postulated that maybe endoscopists are slow to adopt or disagree with new guidelines [1, 21]. A prior study of 10 endoscopists found that they all selected the correct recommendation in a surveillance vignette with one tubular adenoma, and 7 endoscopists did so for a vignette with two tubular adenomas. It demonstrated that endoscopists were aware of the 2020 guidelines, with LRA recommendations continuing to show the poorest compliance [10].

Factors contributing to low adherence rates have been hypothesized to include poor bowel preparation quality, overestimation of cancer risk in adenomatous or hyperplastic polyps, and the presence of multiple comorbidities [22, 25]. A prior study suggested that inadequate bowel preparation only contributed to 17% of premature cases, which is consistent with the finding in our study that bowel preparation was not independently associated with late or early surveillance [20]. Other studies have found that endoscopists who completed training more than 10 years ago or who performed high volumes of colonoscopies were more likely to recommend premature surveillance colonoscopies [10]. In the current study, se excluded patients with poor or equivocal bowel preparation, so this is unlikely to be a factor. We examined other factors such as race, open access vs. gastroenterologist-directed, endoscopist gender, endoscopist experience, and endoscopist age – and found that none of these had a significant association with inappropriate early colonoscopy. Interestingly, female patients were found to be most likely to undergo early colonoscopy. A prior study found that younger age, female sex, and the presence of gastrointestinal symptoms—including abdominal pain and diarrhea—were associated with inappropriate colonoscopy utilization [26].

One of the notable findings of this study was that we found no improvement in 1 st surveillance compliance rates from 2020 to 2025 after the publication of the 2020 recommendations. For the earlier years (e.g. 2020, 2021), it could be argued that endoscopists were slow to adopt updated guidelines; however, in another study, patients with LRAs still had low compliance rates even among endoscopists who correctly identified the 2020 USMSTF recommendations in a survey study [10], suggesting that low compliance could not be fully explained by low guideline awareness. 2020 was also the start of the COVID-19 pandemic, where 33% of patients’ colonoscopies were appropriate for rescheduling in a future year, according to the 2020 USMSTF guidelines [1]. During the pandemic, this was the best time to delay colonoscopies as there was a need to conserve healthcare resources [1]. In this scenario, it seems that the rate of early 1 st surveillance should be lower and thus, compliance rates should be higher. Thus, the theory that endoscopists are slow to adapt to the guidelines may not be correct.

Several strategies have been proposed to improve compliance. One approach is to optimize the EMR to incorporate guideline-based recommendations at two key points of care: immediately after colonoscopy and within primary care, using data already available within the EMR [1]. Automated algorithms – including AI tools - can help auto-populate polyp findings and recommended intervals, thus reducing variability in documentation. Additionally, patient and clinician-directed reminders, including mailed letters, text messages, or portal notifications, may further improve adherence by increasing patient engagement and reducing missed or delayed follow-up [27]. Other proposed solutions include standardized endoscopy report templates to minimize ambiguity in surveillance recommendations, audit-and-feedback programs to provide endoscopists with individualized adherence metrics, and institutional protocols that require verification of prior colonoscopy data before scheduling surveillance exams [28,29,30].

We recognize the strengths and limitations of this study. Importantly, this study was performed at two academic tertiary medical centers, which enhances its generalizability. However, because these are academic medical centers, the findings may not be generalizable to other institutions, such as community hospitals. Our study further examines patterns of premature versus delayed surveillance in relation to the 2020 USMSTF guidelines and evaluates temporal trends following guideline adoption. Some other limitations are that patients older than 75 years were excluded from our analysis, which restricts our ability to interpret surveillance practices in this population, for whom clinical decision-making remains controversial [31]. The sample size was also limited for HPs and SSPs. This was due to a paucity, as expected, of patients who had only hyperplastic polyps (HPs). Additionally, reasons for late and early colonoscopies were not tracked, so alternative explanations for early and late colonoscopies could not be explored. Finally, we also did not assess gastroenterologists’ awareness of the updated guidelines, despite the increased time available for practice adaptation.

In summary, we have shown here that there is a pervasive lack of adherence to 1 st surveillance guidelines for follow-up colonoscopy. Surprisingly, the propensity for this lack of adherence did not improve over a 5-year period after publication of updated 2020 USMSTF guidelines. The data suggest that as a result of early surveillance colonoscopy, substantial endoscopic resources are being allocated to low-risk individuals—such as those with hyperplastic polyps or small tubular adenomas—who derive limited clinical benefit yet contribute significantly to resource utilization. We speculate that novel approaches to guideline implementation are needed.