Table 9

Differentials in infant mortality rates (source: household survey)

Category

Deaths

Child-years

Mortality rate per 1000 child-years

RR

95% CI*

P*

Year (July–June)

2001–2

184

2,218.8

82.9

1

0.72 (for trend P = 0.75)

2002–3

183

2,324.7

78.7

0.95

0.8 – 1.2

2003–4

227

2,659.8

85.3

1.03

0.8 – 1.3

Mother's age at delivery

20–29

261

3,398.7

76.8

1

0.005

30–39

124

1,702.2

72.8

0.95

0.8 – 1.2

40–49

27

364.5

74.1

0.96

0.6 – 1.4

Under 20

181

1,718.8

105.3

1.37

1.1 – 1.7

Mother's education

One or more years

399

5,123.9

77.9

1

0.038

None

194

2,063.6

94.0

1.21

1.0 – 1.4

Sex

Girls

287

3,537.7

81.1

1

0.70

Boys

307

3,665.5

83.8

1.03

0.9 – 1.2

Twins

Singleton

518

6,980.1

74.2

1

<0.0001

Twin

76

223.2

340.5

4.59

3.4 – 6.2

Age

0–27 days

337

574.2

586.9

1

<0.0001

28–365 days

257

6,629.0

38.8

0.07

0.06 – 0.08

Ethnic group of household head

Makonde

220

3,075.8

71.5

1

0.01

Mwera

246

2,867.3

85.8

1.20

1.0 – 1.4

Yao

29

318.7

91.0

1.27

0.8 – 2.0

Other

99

926.2

106.9

1.49

1.2 – 1.9

Gender of household head

Male

478

5,695.9

83.9

1

0.48

Female

116

1,493.2

77.7

0.93

0.7 – 1.1

SES quintile of household

Poorest

109

1,291.1

84.4

1

0.90 (test for trend)

Very poor

122

1,577.9

77.3

0.92

0.7 – 1.2

Poor

102

1,182.1

86.3

1.02

0.8 – 1.4

Less poor

129

1,540.9

83.7

0.99

0.8 – 1.3

Least poor

120

1,513.7

79.3

0.94

0.7 – 1.2

Distance to nearest health facility

<5 km

363

4,778.9

76.0

1

0.02

≥ 5 km

196

2,061.2

95.1

1.25

1.0 – 1.5

Effect of child's age on the relationship between twinning and mortality:

Twins under 28 days (neonates)

Singleton

280

556.6

503.0

1

<0.0001

Twin

57

17.6

3,242.6

6.45

4.5 – 9.2

Twins over 28 days (1–11 m)

Singleton

238

6,423.4

37.1

1

<0.0001

Twin

19

205.6

92.4

2.49

1.5 – 4.0

Effect of child's age on the relationship between maternal education and mortality:

In neonates: Mother's education

≥ 1 year

238

407.4

584.3

1

0.93

None

98

165.9

590.8

1.01

0.8 – 1.3

In 1–11 month olds: Mother's education

≥ 1 year

161

4,716.7

34.1

1

0.003

None

96

1,897.8

50.6

1.48

1.1 – 1.9

Effect of distance from the health facility on the relationship between maternal education and mortality

In those living < 5 km from a health facility: mothers education

≥ 1 year

239

3,466.

68.9

1

None

123

1,305.3

94.2

1.4

1.1 – 1.7

0.005

In those living ≥ 5 km from a health facility: mothers education

≥ 1 year

140

1,421.5

98.5

1

None

56

637.9

87.8

0.9

0.7 – 1.2

0.47

* From Poisson regression, adjusted for clustering from survey design

Armstrong Schellenberg et al. BMC Public Health 2008 8:194   doi:10.1186/1471-2458-8-194