Dutch-TIMELINESS: optimising choledocholithiasis treatment in the Netherlands - protocol of a national implementation project.

introductionThe Dutch guideline 'Gallstone disease' (2016) recommends performing a cholecystectomy within 72 hours following endoscopic retrograde cholangiopancreatography (ERCP) for common bile duct stones to prevent recurrent gallstone-related complications. Nevertheless, guideline adherence in the Netherlands remains low, and the time between ERCP and cholecystectomy often exceeds 72 hours. Our project aims to improve national guideline adherence to 85% or higher and thereby reduce the incidence of gallstone-related complications after ERCP. METHODS AND ANALYSIS: The Dutch-TIMELINESS is a multicentre implementation project using a Multiphase Optimisation Strategy. The project includes 61 Dutch hospitals. In phase 1, all patients undergoing ERCP for choledocholithiasis from 1 January to 31 March 2023 will be analysed to serve as a benchmark. In phase 2, each hospital develops and implements its own tailored protocol in line with the guideline, guided by the benchmark data. In phase 3, from 1 December 2025 to 31 March 2026, the new protocols will be prospectively evaluated with real-time monitoring and refined as necessary. Statistical methods are predefined in the protocol. ETHICS AND DISSEMINATION: The Medical Research Ethics Committees United reviewed the protocol and concluded it does not fall under the scope of the Medical Research Involving Human Subjects Act (WMO). Local institutional research departments and the board of directors reviewed and approved the protocol in all participating hospitals. Results will be published in international peer-reviewed scientific journals and presented at national conferences.