# Comparative study of the short-term outcomes of gastric cancer surgery between Japanese Gastric cancer association-certified and non-certified institutions: a retrospective cohort analysis using a national database in Japan

## TL;DR

This study compared surgical outcomes for gastric cancer in certified versus non-certified hospitals in Japan and found lower mortality in certified institutions.

## Contribution

The study evaluates the impact of a new institutional certification system on gastric cancer surgery outcomes using a national database.

## Key findings

- Certified institutions had significantly lower mortality risks for both distal and total gastrectomies.
- Type A and B certified institutions showed higher complication risks for total gastrectomies compared to non-certified ones.
- The certification system appears to improve institutional quality and reduce surgical mortality.

## Abstract

This study assessed the impact of an institutional certification system that was newly introduced by the Japanese Gastric Cancer Association on short-term surgical outcomes in patients with gastric cancer using data from the National Clinical Database.

A retrospective cohort study of distal gastrectomy and total gastrectomy procedures performed between January 2020 and December 2022 was conducted. The institutions were classified into three categories: type A, type B, and non-certified institutions, in decreasing order of certification stringency. The primary outcome was the incidence of grade ≥ IIIa postoperative complications based on the Clavien–Dindo classification system. The secondary outcome was surgery-related mortality. Logistic regression with risk adjustment, estimated using generalized estimating equations, was used to account for intra-cluster correlation.

There was no significant difference in the risks of distal gastrectomy-related complications across the three institution types. However, type A- (odds ratio (OR) 0.39, 95% confidence interval (CI) 0.31–0.49) and type B-certified institutions (OR 0.59, 95% CI 0.49–0.71) had a significantly lower mortality risk than non-certified ones. On the other hand, Type A- (OR 1.25, 95% CI 1.09–1.44) and type B-certified institutions (OR 1.17, 95% CI 1.03–1.33) had higher risks of postoperative total gastrectomy-related complications than non-certified ones. Nevertheless, type A- (OR 0.41, 95% CI 0.29–0.58) and type B-certified institutions (OR 0.67, 95% CI 0.51–0.88) had significantly lower surgery-related mortality risks than non-certified ones.

Certified institutions demonstrated lower surgical mortality risks, highlighting the benefits of the certification system and the importance of institutional quality.