In 2021, a new classification for grading adverse events (AEs) related to gastrointestinal (GI) endoscopy was introduced: the AGREE classification [1]. This classification aimed to minimize subjectivity in AE assessment and severity grading compared to existing classifications, and allow for easier and more robust comparisons of endoscopic and surgical interventions. The aim of this review was to evaluate the impact and status of the classification three years following its introduction. 

We performed a systematic scoping review to identify articles referencing the original AGREE publication [1] up to March, 2025. Articles were reviewed to evaluate the classification’s global uptake, use for intra- and interdisciplinary comparisons, and comparability with other classifications. Moreover, identified articles were screened to identify complex AE scenarios, defined as (potentially) incorrectly graded AEs, and AEs for which assignment of a severity grade based on the case description was considered challenging. Complex scenarios were discussed in a consensus meeting involving the lead authors of the original AGREE publication. For all scenarios, consensus on grading was reached through discussion among three of the lead authors (K.N., M.V., P.F.) of the original AGREE publication. A selection of illustrative complex scenarios was made and additional recommendations for grading of these scenarios were established. Additionally, articles were screened for AE reporting practices that may impede the accurate definition, interpretation, and comparison of AEs. The identified reporting practices were used to develop a new checklist to guide more standardized AE reporting using the AGREE classification.

A total of 167 unique articles referencing the original AGREE publication were identified, involving 33 countries across five continents. A notable year-over-year increase in annual citations was observed (range: 8 to 83). In terms of intradisciplinary comparisons, the AGREE classification was proven feasible for direct comparison of AEs across (i) different endoscopic treatment modalities in similar patient groups (21 studies), (ii) similar endoscopic treatment modalities in different patient populations or performed by endoscopists with different levels of expertise (8 studies), and (iii) endoscopy units (1 study). In terms of interdisciplinary comparisons, the AGREE classification facilitated comparison of AEs related to endoscopic interventions with both surgical (3 studies, 3 study protocols) and radiology-guided alternatives (1 study). Moreover, a significant correlation between AE severities as graded by the AGREE classification and the American Society for Gastrointestinal Endoscopy (ASGE) classification was reported (2 studies). Concordance in AE severities among clinicians was greater for AEs assessed using the AGREE compared to the ASGE classification (κ = 0.80 vs. 0.60) [2]. In terms of complex scenarios, nine illustrative scenarios were selected, for which consensus-based recommendations were established. Based on identified (variability in) AE reporting practices, a checklist to guide standardized AE reporting was composed (key recommendations included in Table 1). 

This review illustrates the rapid uptake of the AGREE classification and outlines its feasibility to facilitate intra- and interdisciplinary comparisons, along with greater interobserver agreement in AE severity grading when compared to other classifications. Findings of this review highlight the potential of the AGREE classification to serve as a widely accepted classification for GI endoscopy-related AEs. The extended recommendations provided in this review could help to further standardize the identification, grading, and reporting of AEs, thereby increasing opportunities for evaluating and optimizing quality of GI endoscopy.