Table 3 Multilevel analysis of factors associated with preterm birth among reproductive age women from Sub-Saharan African countries

 Urban

1

1

 Rural

1.21 (1.15 1.27)

1.13 (1.04, 1.22) *

 central Africa

1

1

 east Africa

4.6 (4.06, 5.10)

4.88 (4.25, 5.61)*

 South Africa

7.30 (6.4 8.46)

1.83 (1.58, 2.12)*

 West Africa

1.77 (1.57, 1.99)

1.17 (0.89, 1.32)

 < 20

1.03 (0.92, 1.15

1.12 (1.01, 1.25)*

 20–34

1

1

 > 34

0.95 (0.91, 1.06)

0.96 (0.92, 1.07)

 No

1

1

 Primary

2.40 (2.25, 2.56)

1.53 (1.43, 1.65)*

 Secondary

1.73 (1.59, 1.89)

1.36 (1.25, 1.49) *

 higher

1.75(1.49, 1.2.05)

1.42 (1.21, 1.67) *

 Single

1

1

 Married

0.91 (0.85, 0.97)

0.89 (0.84, 0.93) *

 Divorced

1.29 (1.08,1.49)

1.07 (0.93, 1.24)

 widowed

1.09 (0.86, 1.39)

0.94 (0.74, 1.28)

 Poorest

1

1

 poorer

0.70 (0.65, 0.76)

0.75 (0.69, 0.81) *

 Middle

0.65 (0.59, 0.70)

0.69 (0.64, 0.76) *

 richer

0.74 (0.68, 0.81)

0.75 (0.69, 0.82) *

 Richest

0.88 (0.80, 0.97)

0.82 (0.73, 0.91)*

 No

1

1

 Yes

1.11 (1.05, 1.18)

1.12 (1.05, 1.18)*

 No

1

1

 Yes

1.04 (0.99, 1.11)

1.03 (0.96, 1.12)

Substance use

 No

1

1

 Yes

1.25 (1.18, 1.36)

1.27 (1.09, 1.63) *

 First birth

2.04 (1.89, 2.21)

1.88 (1.74, 2.05) *

 <  24 months

1.14 (1.06, 1.22)

1.21 (1.13, 1.31) *

 24–59 months

1

1

 >  60 months

1.07 (0.98, 1.17)

1.01 (0.92, 1.11)

 < 4 visits

1

1

 ≥ 4 visits

0.78 (0.74, 0.82)

0.78 (0.74, 0.83) *

 Male

1

1

 Female

1.08 (1.03, 1.15)

1.08 (1.03, 1.15) *

 No

1

 Yes

3.18 (2.87, 3.52)

3.37 (3.04, 3.74)*

 No

1

1

 Yes

1.24 (1.16, 1.34)

1.21 (1.13, 1.31) *

 No

1

1

 Yes

0.65 (0.59, 0.71)

0.75 (0.68, 0.83) *

 No

1

1

 Yes

1.62 (1.44, 1.84)

1.46 (1.29, 1.65) *

 Community level variance

0.36

0.32

0.23

0.19

 ICC (%)

9.9%

8.8%

6.5%

5.5%

 MOR

1.41

1.34

1.24

1.19

 PCV (%)

reference

11.11%

36.11%

47.22%

 Deviance

72,624

70,337

47,244

45, 945