Case-mix adjustment to compare nationwide hospital performances after resection of colorectal liver metastases

Arthur K E Elfrink*, Erik W van Zwet, Dutch Hepato Biliary Audit Group, Rutger-Jan Swijnenburg, Marcel den Dulk, Peter B van den Boezem, J Sven D Mieog, Wouter W Te Riele, Gijs A Patijn, Wouter K G Leclercq, Daan J Lips, Arjen M Rijken, Cornelis Verhoef, Koert F D Kuhlmann, Carlijn I Buis, Koop Bosscha, Eric J T Belt, Maarten Vermaas, N Tjarda van Heek, Steven J OosterlingHans Torrenga, Hasan H Eker, Esther C J Consten, Hendrik A Marsman, Michel W J M Wouters, Niels F M Kok, Dirk J Grünhagen, Joost M Klaase

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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BACKGROUND: Differences in patient demographics and disease burden can influence comparison of hospital performances. This study aimed to provide a case-mix model to compare short-term postoperative outcomes for patients undergoing liver resection for colorectal liver metastases (CRLM).

METHODS: This retrospective, population-based study included all patients who underwent liver resection for CRLM between 2014 and 2018 in the Netherlands. Variation in case-mix variables between hospitals and influence on postoperative outcomes was assessed using multivariable logistic regression. Primary outcomes were 30-day major morbidity and 30-day mortality. Validation of results was performed on the data from 2019.

RESULTS: In total, 4639 patients were included in 28 hospitals. Major morbidity was 6.2% and mortality was 1.4%. Uncorrected major morbidity ranged from 3.3% to 13.7% and mortality ranged from 0.0% to 5.0%. between hospitals. Significant differences between hospitals were observed for age higher than 80 (0.0%-17.1%, p < 0.001), ASA 3 or higher (3.3%-36.3%, p < 0.001), histopathological parenchymal liver disease (0.0%-47.1%, p < 0.001), history of liver resection (8.1%-36.3%, p < 0.001), major liver resection (6.7%-38.0%, p < 0.001) and synchronous metastases (35.5%-62.1%, p < 0.001). Expected 30-day major morbidity between hospitals ranged from 6.4% to 11.9% and expected 30-day mortality ranged from 0.6% to 2.9%. After case-mix correction no significant outliers concerning major morbidity and mortality remained. Validation on patients who underwent liver resection for CRLM in 2019 affirmed these outcomes.

CONCLUSION: Case-mix adjustment is a prerequisite to allow for institutional comparison of short-term postoperative outcomes after liver resection for CRLM.

Original languageEnglish
Pages (from-to)649-659
Number of pages11
JournalEuropean Journal of Surgical Oncology
Issue number3
Publication statusPublished - Mar 2021

Bibliographical note

Copyright © 2020 University Medical Center Groningen. Published by Elsevier Ltd.. All rights reserved.


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