Variable | Cases N=1119 | Controls N=209 941 | Unadjusted OR (95% CI) | Adjusted* OR (95% CI) |
---|---|---|---|---|
Socioeconomic category (IRSD quintile) | ||||
1 (least deprived) | 209 (18.7) | 45 167 (21.5) | 1.0 | 1.0 |
2 | 246 (22.0) | 44 242 (21.2) | 1.20 (1.00 to 1.44) | 1.23 (1.03 to 1.49) |
3 | 156 (13.9) | 35 948 (17.1) | 0.94 (0.76 to 1.15) | 0.98 (0.79 to 1.21) |
4 | 241 (21.5) | 35 522 (16.9) | 1.47 (1.22 to 1.77) | 1.55 (1.28 to 1.87) |
5 (most deprived) | 231 (20.6) | 44 371 (21.1) | 1.13 (0.93 to 1.36) | 1.21 (1.00 to 1.47) |
Missing | 36 (3.2) | 4509 (2.2) | 1.73 (1.21 to 2.46) | 1.74 (1.21 to 2.50) |
Patient accommodation class | ||||
Private | 368 (32.9) | 74 027 (35.3) | 0.90 (0.79 to 1.02) | † |
Public | 751 (67.1) | 135 914 (64.7) | 1.0 | |
Age category (years) | ||||
<20 | 40 (3.6) | 5782 (2.8) | 1.29 (0.92 to 1.80) | 1.14 (0.81 to 1.60) |
20–24 | 103 (9.2) | 23 987 (11.4) | 0.80 (0.64 to 1.00) | 0.78 (0.62 to 0.98) |
25–29 | 284 (25.4) | 52 878 (25.2) | 1.0 | 1.0 |
30–34 | 339 (30.3) | 73 852 (35.2) | 0.86 (0.73 to 1.00) | 0.87 (0.74 to 1.02) |
≥35 | 353 (31.6) | 53 434 (25.5) | 1.23 (1.05 to 1.44) | 1.22 (1.04 to 1.44) |
Missing | 0 | 8 | Omitted | |
Country of birth (region) | ||||
Australia | 860 (76.9) | 154 794 (73.7) | 1.0 | 1.0 |
Oceania | 24 (2.1) | 5792 (2.8) | 0.75 (0.50 to 1.12) | 0.78 (0.52 to 1.18) |
UK and Ireland | 29 (2.6) | 5378 (2.6) | 0.97 (0.67 to 1.41) | 0.98 (0.67 to 1.42) |
Europe | 23 (2.1) | 6064 (2.9) | 0.68 (0.45 to 1.03) | 0.73 (0.48 to 1.10) |
Middle East | 11 (1.0) | 4484 (2.1) | 0.44 (0.24 to 0.80) | 0.48 (0.26 to 0.87) |
North America | 6 (0.5) | 1291 (0.6) | 0.84 (0.37 to 1.87) | 0.87 (0.39 to 1.94) |
South America | 3 (0.3) | 1267 (0.6) | 0.43 (0.14 to 1.33) | 0.43 (0.14 to 1.35) |
Africa | 28 (2.5) | 5292 (2.5) | 0.95 (0.65 to 1.39) | 1.03 (0.71 to 1.51) |
Asia | 133 (11.9) | 24 675 (11.8) | 0.97 (0.81 to 1.17) | 1.06 (0.88 to 1.27) |
Missing | 2 (0.2) | 904 (0.4) | 0.40 (0.10 to 1.60) | 0.39 (0.10 to 1.59) |
ATSI | ||||
Non-ATSI | 1095 (97.9) | 207 839 (99.0) | 1.0 | 1.0 |
ATSI | 23 (2.1) | 1959 (0.9) | 2.23 (1.47 to 3.38) | 2.02 (1.32 to 3.09) |
Missing | 1 (0.1) | 143 (0.1) | 1.33 (0.19 to 9.50) | 1.16 (0.16 to 8.44) |
Marital status | ||||
Married | 795 (71.1) | 150 450 (71.7) | 1.0 | † |
Single | 145 (13.0) | 27 939 (13.3) | 0.98 (0.82 to 1.17) | |
De facto | 178 (15.9) | 31 081 (14.8) | 1.08 (0.92 to 1.28) | |
Missing | 1 (0.1) | 471 (0.2) | 0.40 (0.06 to 2.86) |
*Variables included in the multivariable model: socioeconomic quintile, maternal age, country of birth, ATSI status, parity, multiple pregnancy, coexisting medical condition, past caesarean section and past spontaneous abortion.
†Not included in multivariable model as either it did not contribute significantly to the fit of the model, or was on the causal pathway (mode of delivery) or considered an outcome (ICU/HDU admission).
ATSI, Aboriginal and Torres Strait Islander; HDU, high dependency unit; ICU, intensive care unit; IRSD, Index of Relative Socioeconomic Disadvantage.