Table 2 Distribution of women’s characteristics, and their association with the median time to second birth in Nigeria and South Africa

Fertility desired

0.046*

 < .001***

No more

9047(30.9)

97.8

36(35–37)

3877(64.2)

80.1

64(62–66)

Wanted

18,283(62.4)

76.6

34(34–35)

1828(30.3)

39.8

105(96–115)

Undecided

1966(6.7)

90.9

35(34–36)

334(5.5)

54.8

83(74–93)

Contraceptive use

 < .001***

 < .001***

Never

19,898(67.9)

82.5

35(34–35)

1350(22.4)

64.5

78(73–84)

Formal

4643(15.8)

86.6

37(36–37)

1295(21.4)

66.8

72(68–76)

Current

4755(16.2)

88.5

35(34–36)

3394(56.2)

67.1

69(67–71)

Contraception/desire

 < .001***

 < .001***

Never/no-more

5377(18.4)

96.8

35(35–36)

872(14.4)

75.5

68(63–72)

Never/want

13,267(45.3)

76.1

34(34–35)

357(5.9)

42.6

121(99–139)

Never/undecided

1254(4.3)

89.4

34(33–35)

121(2.0)

50.4

97(84–124)

Former/no-more

1649(5.6)

98.8

38(37–39)

783(13.0)

82.8

63(59–66)

Former/want

2626(9.0)

78.2

36(35–37)

447(7.4)

40.0

124(98–143)

Former/undecided

368(1.3)

91.3

37(35–39)

65(1.1)

58.5

95(70–116)

Current/no-more

2021(6.9)

99.8

36(35–38)

2222(36.8)

81.0

63(60–65)

Current/want

2390(8.2)

77.9

34(33–35)

1024(17.0)

38.7

93(82–103)

Current/undecided

344(1.2)

95.9

36(33–38)

148(2.5)

56.8

71(62–82)

Ethnicity

 < .001***

0.003**

Hausa

11,048(37.7)

87.6

33(33–33)

Igbo

4220(14.4)

82.1

34(33–34)

Yoruba

3619(12.4)

81.3

41(40–42)

Don’t know/others

10,409(35.5)

82.3

36(36–37)

Black/African

5259(87.1)

65.8

72(70–74)

White

131(2.2)

77.9

50(37–60)

Coloured

594(9.8)

69.0

74(67–77)

Indian/Asian/other

55(0.9)

74.5

69(49–87)

Residence

 < .001***

 < .001***

Urban

10,970(37.4)

82.9

36(36–37)

3373(55.9)

64.3

76(74–78)

Rural

18,326(62.6)

84.9

34(34–35)

2666(44.1)

69.3

66(64–69)

Religion

 < .001***

Christianity

13,444(45.9)

80.9

37(37–37)

Islam

15,582(53.2)

87.0

34(33–34)

Traditionalist/other

270(0.9)

84.4

33(31–35)

Age at FB

 < .001***

 < .001***

 < 20

16,601(56.7)

87.8

35(34–35)

2857(47.3)

71.5

71(69–74)

20–24

8509(29.0)

81.6

35(35–36)

2293(38.0)

65.9

70(68–73)

 ≥ 25

4186(14.3)

74.8

36(35–37)

889(14.7)

52.0

77(70–84)

Wealth index

 < .001***

 < .001***

Low

10,208(34.8)

86.4

34(33–34)

2168(35.9)

69.2

64(62–67)

Middle

10,313(35.2)

84.5

35(35–35)

2139(35.4)

66.6

72(69–75)

High

8775(30.0)

81.0

37(37–38)

1732(28.7)

63.0

80(77–85)

Education

 < .001***

 < .001***

No education

12,207(41.7)

89.0

33(33–34)

158(2.6)

87.3

55(50–62)

Primary

5210(17.8)

89.9

36(35–37)

697(11.5)

83.8

58(55–63)

Secondary

9319(31.8)

76.7

37(36–37)

4547(75.3)

64.3

74(71–76)

Higher

2560(8.7)

76.3

37(36–38)

637(10.5)

57.8

78(71–84)

Employment

 < .001***

 < .001***

Not working

8172(27.9)

78.6

33(33–34)

3702(61.3)

63.4

67(66–70)

Working

21,124(72.1)

86.3

36(35–36)

2337(38.7)

71.4

77(75–80)

Marital at FB

 < .001***

 < .001***

Never married

903(3.1)

32.2

91(83–104)

2956(48.9)

52.3

82(79–85)

Married before FB

25,025(85.4)

84.9

34(34–35)

1297(21.5)

77.6

60(58–62)

Married after FB

3368(11.5)

92.6

37(37–38)

1786(29.6)

81.8

69(66–73)

FB sex

0.676

0.965

Male

15,019(51.3)

84.0

35(35–35)

3138(52.0)

66.4

71(69–74)

Female

14,277(48.7)

84.2

35(35–35)

2901(48.0)

66.5

72(69–75)

FB survival

 < .001***

0.488

Dead

1958(6.7)

85.6

31(31–32)

219(3.6)

69.4

64(56–83)

Alive

27,338(93.3)

84.0

35(35–35)

5820(96.4)

66.4

71(70–74)

Total

29,296

84.1/0!

35(35–35)

6039

66.5

71(70–73)