Table 3 Adjusted odds ratio for factors associated with non-registration, New South Wales, Australia, 2001–2005 (n = 398,730*)

Indigenous status*

Indigenous

12,626

3.26

3.10

3.43

Non-Indigenous

386,104

1

Maternal age*

25–39

311,542

1.00

<25 or >39

87,188

2.81

2.72

2.90

Birthweight (grams)*

≥2500g

375,296

1

<2500g

23,434

1.79

1.69

1.90

Plurality

Single

385,990

1

Plural

12,740

0.84

0.76

0.92

Quarters*^b

First

103,861

1

Second

104,183

1.08

1.03

1.12

Third

108,516

1.30

1.24

1.35

Fourth

82,170

1.56

1.49

1.64

Number of previous pregnancies*

0

167,942

1

1

134,661

1.85

1.78

1.93

2

60,543

3.06

2.92

3.20

3

21,751

4.71

4.46

4.98

4+

13,833

7.29

6.87

7.73

Remoteness*

Major cities

300,897

1

Other areas

97,833

1.57

1.52

1.63

Mother’s country of birth*

Australia

285,335

1

Other countries

113,395

0.72

0.69

0.75

Neonatal or postneonatal death

No

397,663

1

Yes

1,067

3.84

3.23

4.57

Year of birth

2001

80,050

1

2002

82,985

8.96

7.98

10.06

2003

84,932

16.08

14.36

18.00

2004

84,039

17.39

15.54

19.47

2005

66,724

25.14

22.44

28.16