Elsevier

Journal of Critical Care

Volume 47, October 2018, Pages 232-237
Journal of Critical Care

Sepsis/Infection
Hospital variability of postoperative sepsis and sepsis-related mortality after elective coronary artery bypass grafting surgery

https://doi.org/10.1016/j.jcrc.2018.07.018Get rights and content

Highlights

  • Rates of postoperative sepsis, hospital mortality and readmission varied between and within public and private hospitals.

  • Private hospitals had reduced rates of sepsis incidence, hospital mortality and readmission compared to public hospitals.

  • Significant differences persisted in CABG outcomes between the worst and best performing public and private hospitals.

Abstract

Purpose

Hospital variability of postoperative sepsis and sepsis-related mortality after elective CABG surgery was not known in Australia.

Material and methods

Population-based analysis of all elective patients who underwent CABG surgery in public and private hospitals between 2007 and 2014 using linked data from the state-wide Admitted Patient Data Collection and the NSW Registry of Births, Deaths, and Marriages.

Results

We identified 18,928 (9464 pairs) matched patients who had elective CABG surgery in public hospitals (n = 9) and private hospitals (n = 13) during the study period. When compared to public hospital patients, private hospital patients had a significantly lower rate of post-CABG sepsis (13.3 vs 20.4 per 1000 admissions, P < 0.001; treatment effects: −7.1, 95%CI: −11.1 to −3.3), a lower in-hospital mortality rate (6.1 vs 9.9 per 1000 admissions, P = 0.006; treatment effects: −3.8, 95%CI: −6.5 to −1.1), and a lower rate of 30-day readmission (11.9% vs 13.9%, P < 0.001; treatment effects: −2.0%, 95%CI: −3.1% to −1.0%). In addition, for both public and private hospital groups, there were significant differences for all outcomes when comparing the worst and best performance quintile hospitals.

Conclusions

Hospital variability of postoperative sepsis, in-hospital mortality and readmission after elective CABG existed between and within public and private hospitals.

Introduction

In Australia, >25,000 CABG procedures are performed each year, amounting to >100 per 100,000 general population [1] Given the use of a standardised surgical technique and well-established guidelines [2], it might be expected that variations in surgical complications, mortality and readmissions would be limited. However, outcomes and complications have been reported to vary widely across hospitals [3,4]. In addition, perioperative complications, including sepsis, have been identified as significant risk factors for death and early readmission [3,5].These observations from the USA suggest that there is the potential to improve the care and outcomes of these patients by understanding the extent and nature of such variation in Australia, especially in the area of postoperative sepsis.

Postoperative sepsis is a major, and potentially preventable, complication of cardiac surgery. The variability in post CABG or cardiac surgery-associated sepsis related mortality reached a three-fold difference between the worst and best quintile hospitals [6]. In Australia, similar variation was seen among all cardiac surgery patients [7]. For isolated CABGs, another Australian study found a 5.6%–9.9% complication rate, and a 5.4%–23.1% complication-related mortality rate between the best and worst quintile hospitals, but focused only on patients admitted to public hospitals [8]. The findings from these two Australian studies were based on pooled elective, urgent and emergency operations [7] or elective operations only in public hospitals [8], and the outcomes of patients operated in private hospitals was not assessed.

To understand the full extent and impact of variation in outcomes and complications across the whole health care sector, we aimed to explore the outcomes, and variation in outcomes, in relation to sepsis, sepsis-related mortality and sepsis-related complications for all elective CABG surgery for both public and private hospitals in the state of New South Wales (NSW), Australia.

Section snippets

Data source and study population

We conducted a population-based retrospective cohort study using the NSW administrative data from the Admitted Patient Data Collection (APDC). Briefly, the APDC includes information on patient demographics, medical conditions and procedures, hospital characteristics, and separations (discharges, transfers and deaths) from all public and private hospitals in NSW [9]. The medical records for each episode of care in the APDC were assigned codes based on the International Classification of Diseases

Description

A total of 20,543 patients undergoing elective CABG procedures met the selection criteria between 1 January 2007 and 31 March 2014. Of these, 11,074 (53.9%) patients were admitted to public hospitals (n = 9), and 9469 (46.1%) were admitted to private hospitals (n = 13). Patient and hospital characteristics before nearest neighbour matching are provided in Table S1 (Supplementary material: Table S1) in the Supporting information and the selected characteristics of the study patients after

Key findings

We performed a population-based retrospective study and compared sepsis-related outcomes and their variability among patients having elective CABG surgery between, and within, public and private hospitals in a large health jurisdiction over seven years. We found that patients in private hospitals had a reduced sepsis incidence and in-hospital mortality rate, as well as reduced readmission rate compared with patients from public hospitals. However, we also found significant differences in all

Conclusions

There were significant differences in the rates of postoperative sepsis, in-hospital mortality and 30-day post-discharge readmission after elective CABG surgery between public hospitals and private hospitals. There were also significant variations in all sepsis-related outcomes within public and private hospitals. Further research is warranted to explore the potential contributing factors to these variations and to develop interventional strategies to decrease the variation.

Funding

This work was supported by the National Health and Medical Research Council (NHMRC: ID1020660; ID1009916), Australia.

Conflict of interest

None declared.

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