Adverse outcome after incident stroke hospitalization for Indigenous and non-Indigenous Australians in the Northern Territory.
BACKGROUND
Survival after a stroke is lower for Indigenous than other stroke patients in Australia. It is not known whether recurrence is more common for Indigenous patients, or whether their higher prevalence of comorbidity affects their lower survival.


OBJECTIVE
This study aimed to investigate the stroke recurrence and role of comorbidities in adverse stroke outcomes (recurrence and death) for Indigenous compared with other Australians.


METHODS
A retrospective cohort study of first hospitalization for stroke (n = 2105) recorded in Northern Territory hospital inpatient data between 1996 and 2011 was conducted. For the multivariable analyses of adverse outcomes, logistic regression was used for case fatality and competing risk analysis for recurrent stroke and long-term death. Comorbidities (identified from inpatient diagnosis data) were analyzed using the Charlson Comorbidity Index (modified for stroke outcomes).


RESULTS
Prevalence of comorbidities, case fatality, incidence of re-hospitalization for recurrent stroke, and long-term death rate were higher for Indigenous than non-Indigenous stroke patients. Adjustment for comorbidity in multivariable analyses considerably reduced Indigenous patients' excess risk for case fatality (odds ratio: 1·25, 0·88-1·78) and long-term death (standard hazard ratio: 1·27, 1·01-1·61) (but not recurrence), implying that their excess risk of death was in part due to higher comorbidity prevalence.


CONCLUSIONS
Indigenous stroke patients have higher prevalence of comorbidities than non-Indigenous stroke patients, which explained part of the disparity in both case fatality and long-term survival but did not explain the disparity in stroke recurrence at all.
Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
Vincent Y F
VY
He
Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
John R
JR
Condon
Department of Health, Northern Territory Government, Darwin, NT, Australia.
Jiqiong
J
You
Department of Health, Northern Territory Government, Darwin, NT, Australia.
Yuejen
Y
Zhao
Royal Darwin Hospital, NT Department of Health, Darwin, NT, Australia.
James N
JN
Burrow
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015876:Northern Territory / Q000453:epidemiology; D044382:Population Groups; D012044:Regression Analysis; D020521:Stroke / Q000453:epidemiology* / Q000208:ethnology* / Q000401:mortality
Indigenous Australian; comorbidity; competing risks; hospital data; recurrent stroke; survival analysis