Critically ill Indigenous Australians and mortality: a complex story

Indigenous Australians critically ill with sepsis: Characteristics, outcomes, and areas for improvement

BACKGROUND

Aboriginal and Torres Strait Islander Australians have amongst the highest incidence of sepsis globally.

OBJECTIVE

The objective of this study was to describe the characteristics, short- and long-term outcomes of non-Indigenous, Aboriginal Australian and Torres Strait Islander Australians admitted with sepsis to an intensive care unit (ICU) to inform healthcare outcome improvement.

METHODS

A retrospective cohort study of 500 consecutive sepsis admissions to the Cairns Hospital ICU compared clinical characteristics, short-term (before ICU discharge) and long-term (2000 days posthospital discharge) outcomes. Cohort stratification was done by voluntary disclosure of Indigenous status.

RESULTS

Of the 442 individual admissions, 145 (33%) identified as Indigenous Australian. Indigenous and non-Indigenous Australians had similar admission Acute Physiology and Chronic Health Evaluation-3 scores (median [interquartile range]: 70 [52-87] vs. 69 [53-87], P = 0.87), but Indigenous patients were younger (53 [43-60] vs. 62 [52-73] years, P < 0.001) and were more likely to have chronic comorbidities such as type 2 diabetes (58% vs. 23%, P < 0.001), cardiovascular disease (40% vs 28%, P = 0.01), and renal disease (39% vs. 10%, P < 0.001). They also had more hazardous healthcare behaviours such as smoking (61% vs. 45%, P = 0.002) and excess alcohol consumption (40% vs. 18%, P < 0.001). Despite this, the case-fatality rate of Indigenous and non-Indigenous Australians before ICU discharge (13% vs. 12%, P = 0.75) and 2000 days post hospital discharge (25 % vs. 28 %, P = 0.40) was similar. Crucially, however, Indigenous Australians died younger both in the ICU (median [interquartile range] 54 (50-60) vs. 70 [61-76], P < 0.0001) and 2000 days post hospital discharge (58 [53-63] vs. 70 [63-77] years, P < 0.0001).

CONCLUSIONS

Although Indigenous Australians critically ill with sepsis have similar short and long-term mortality rates, they present to hospital, die in-hospital, and die post-discharge significantly younger. Unique cohort characteristics may explain these outcomes, and assist clinicians, researchers and policy-makers in targeting interventions to these characteristics to best reduce the burden of sepsis in this cohort and improve their healthcare outcomes.

Associations Between Socioeconomic Status, Patient Risk, and Short-Term Intensive Care Outcomes

OBJECTIVES

To investigate the association of socioeconomic status as measured by the average socioeconomic status of the area where a person resides on short-term mortality in adults admitted to an ICU in Queensland, Australia.

DESIGN

Secondary data analysis using de-identified data from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation linked to the publicly available area-level Index of Relative Socioeconomic Advantage and Disadvantage from the Australian Bureau of Statistics.

SETTING

Adult ICUs from 35 hospitals in Queensland, Australia, from 2006 to 2015.

PATIENTS

A total of 218,462 patient admissions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The outcome measure was inhospital mortality. The main study variable was decile of Index of Relative Socioeconomic Advantage and Disadvantage. The overall crude inhospital mortality was 7.8%; 9% in the most disadvantaged decile and 6.9% in the most advantaged decile (p < 0.001). Increasing socioeconomic disadvantage was associated with increasing severity of illness as measured by Acute Physiology and Chronic Health Evaluation III score, admission with a diagnosis of sepsis or trauma, cardiac, respiratory, renal, and hepatic comorbidities, and remote location. Increasing socioeconomic advantage was associated with elective surgical admission, hematological and oncology comorbidities, and admission to a private hospital (all p < 0.001). After excluding patients admitted after elective surgery, in the remaining 106,843 patients, the inhospital mortality was 13.6%, 13.3% in the most disadvantaged, and 14.1% in the most advantaged. There was no trend in mortality across deciles of socioeconomic status after excluding elective surgery patients. In the logistic regression model adjusting for severity of illness and diagnosis, there was no statistically significant difference in the odds ratio of inhospital mortality for the most disadvantaged decile compared with other deciles. This suggests variables used for risk adjustment may lie on the causal pathway between socioeconomic status and outcome in ICU patients.

CONCLUSIONS

Socioeconomic status as defined as Index of Relative Socioeconomic Advantage and Disadvantage of the area in which a patient lives was associated with ICU admission diagnosis, comorbidities, severity of illness, and crude inhospital mortality in this study. Socioeconomic status was not associated with inhospital mortality after excluding elective surgical patients or when adjusted for severity of illness and admission diagnosis. Commonly used measures for risk adjustment in intensive care improve understanding of the pathway between socioeconomic status and outcomes.