Implementation of a Structured Perioperative Checklist-Based Standardization Process and Early Postoperative Outcomes After Bariatric Surgery: A Single-Center Retrospective Pre–Post Cohort Study

Background/Objectives: Structured perioperative checklists may standardize bariatric surgical care, but their association with early clinical outcomes remains uncertain. This study compared 30-day postoperative outcomes before and after implementation of a structured perioperative checklist and characterized complications by type and Clavien–Dindo severity.

Methods

This single-center retrospective pre–post cohort study included patients undergoing primary bariatric surgery from June 2024 through December 2025. The checklist was prospectively introduced on 29 July 2024. Cohort identification, data extraction, outcome classification, and comparative analyses were performed retrospectively. Forty patients were included in each cohort. The primary outcome was any 30-day postoperative complication; secondary outcomes included complication severity, intensive care unit admission, and length of hospital stay. Checklist implementation was assessed on the basis of documented completion; item-level adherence to individual perioperative measures and corrective actions prompted by checklist responses were not assessed. Accordingly, the intervention evaluated in this study represents implementation of a structured checklist-based documentation and care-standardization process rather than verified adherence to individual checklist components.