Establishing a quantitative benchmark for morbidity in pancreatoduodenectomy using ACS-NSQIP, the Accordion Severity Grading System, and the Postoperative Morbidity Index

Abstract

Objective: The study aim was to quantify the burden of complications of pancreatoduodenectomy (PD).

Background: The Postoperative Morbidity Index (PMI) is a quantitative measure of the average burden of complications of a procedure. It is based on highly validated systems--ACS-NSQIP and the Modified Accordion Severity Grading System.

Methods: Nine centers contributed ACS-NSQIP complication data for 1589 patients undergoing PD from 2005 to 2011. Each complication was assigned a severity weight ranging from 0.11 for the least severe complication to 1.00 for postoperative death, and PMI was derived. Contribution to total burden by each complication grade was used to generate a severity profile ("spectrogram") for PD. Associations with PMI were determined by regression analysis.

Results: ACS-NSQIP complications occurred in 528 cases (33.2%). The non-risk-adjusted PMI was 0.115 (SD = 0.023) for all centers and 0.113 (SD = 0.005) for the 7 centers that contributed at least 100 cases. Grade 2 complications were predominant in frequency, and the most common complication was postoperative bleeding/transfusion. Frequency and burden of complications differed markedly. For instance, severe complications (grades 4/5/6) accounted for only about 20% of complications but for more than 40% of the burden of complications. Organ space infection had the highest burden of any complication. The average burden in cases in which a complication actually occurred was 0.346.

Conclusions: This study develops a quantitative non-risk-adjusted benchmark for postoperative morbidity of PD. The method quantifies the burden of types and grades of postoperative complications and should prove useful in identifying areas that require quality improvement.