Advancing quality of colonoscopy Performance measures and technical innovations

Colonoscopy is central to diagnosing colorectal diseases and preventing colorectal cancer, yet its effectiveness depends on procedural quality. This thesis examines quality monitoring, procedural safety, patient experience, and the evaluation and implementation of technical innovations.
The first part focuses on polyp detection and resection completeness. Automated linkage between the Dutch endoscopy (DGEA) and pathology (PALGA) registries was feasible in 94% of centers, enabling large-scale monitoring of the adenoma detection rate (ADR) and revealing substantial inter-center variation in ADR. A systematic review identified heterogeneous methods for assessing the completeness of colorectal polyp resections, informing an international Delphi consensus that established standardized assessment protocols for polyps smaller than 20 mm.
The second part examines adverse events (AEs) and patient experience. Uptake of the AGREE classification for endoscopy-related AEs increased markedly, and additional recommendations were provided to standardize AE assessment and reporting. Cold snare polypectomy of polyps smaller than 10 mm in patients continuing high-dose antithrombotic therapy was associated with a low bleeding risk (0.58%), comparable to that in patients on low-dose antithrombotic therapy. Clinician-reported pain and discomfort scores matched patient-reported scores in only about half of cases, highlighting the importance of using validated patient-reported experience measures. National data showed increased use of propofol-based sedation between 2020 and 2024 and substantial inter-center variation in midazolam-based sedation practices across Dutch endoscopy centers.
The third part evaluates technical innovations. Computer-aided detection did not improve ADR during Lynch syndrome surveillance in expert settings. Advances in computer-aided polyp characterization were shown to primarily involve optical differentiation between neoplastic and non-neoplastic polyps. A virtual scale tool reduced variability in polyp size measurement.
These findings support colonoscopy quality improvement through automated monitoring, standardized assessment, patient-reported outcomes, and evidence-based technology adoption.