Table 5 Sensitivity analyses using different Aboriginal identification definitions, 90-day events, comorbidity look-back periods, hospital type and 28-day deaths

(i) Definition of Aboriginal identification

Any admission*

0.96 (0.89-1.04)

0.36

0.87 (0.79-0.97)

0.01

0.95 (0.88-1.02)

0.16

0.88 (0.77-0.99)

0.04

≥25% of admissions

0.95 (0.88-1.04)

0.27

0.89 (0.79-1.00)

0.05

0.94 (0.87-1.02)

0.13

0.87 (0.76-1.01)

0.07

First admission for the event

0.96 (0.88-1.05)

0.33

0.90 (0.80-1.02)

0.09

0.93 (0.86-1.01)

0.10

0.87 (0.75-1.01)

0.08

(ii) Definition of event duration

28-day event (Aboriginal any admission)*

0.96 (0.89-1.04)

0.36

0.87 (0.79-0.97)

0.01

0.95 (0.88-1.02)

0.16

0.88 (0.77-0.99)

0.04

90-day event (Aboriginal any admission)

0.94 (0.87-1.01)

0.10

0.87 (0.79-0.96)

<0.01

0.96 (0.89-1.02)

0.19

0.87 (0.77-0.98)

0.02

(iii) Different comorbidity look-back periods

1-year

0.95 (0.88-1.03)

0.18

0.84 (0.75-0.93)

0.001

0.94 (0.88-1.01)

0.12

0.86 (0.75-0.97)

0.002

2-year

0.96 (0.89-1.04)

0.29

0.85 (0.76-0.94)

0.002

0.95 (0.88-1.02)

0.17

0.86 (0.76-0.98)

0.02

5-year

0.96 (0.89-1.04)

0.35

0.86 (0.77-0.95)

0.003

0.95 (0.88-1.02)

0.17

0.87 (0.77-0.99)

0.03

10-year

0.96 (0.89-1.04)

0.36

0.86 (0.77-0.95)

0.003

0.95 (0.88-1.02)

0.14

0.87 (0.76-0.98)

0.03

15-year*

0.96 (0.89-1.04)

0.36

0.87 (0.79-0.97)

0.01

0.95 (0.88-1.02)

0.16

0.88 (0.77-0.99)

0.04

(iv) Model 6a + hospital type at initial admission

0.96 (0.88-1.04)

0.31

0.88 (0.80-0.98)

0.02

0.95 (0.88-1.02)

0.15

0.88 (0.77-0.99)

0.04

(v) Model 6a with inclusion of events where patients died within 28days

0.97 (0.90-1.05)

0.46

0.88 (0.79-0.97)

0.01

0.96 (0.89-1.03)

0.25

0.88 (0.78-1.00)

0.06