Table 3 Two-level poisson regression results on factors associated with the birth certification of children under-5 in Nigeria DHS 2008–2018, (n = 66,630)

Age

0–11

1

1

12–23

0.930(0.849–1.020)

0.930(0.848–1.018)

24–35

0.904(0.777–1.051)

0.900(0.775–1.047)

36–47

0.893(0.727–1.097)

0.890(0.725–1.092)

48–59

0.695(0.532–0.907)***

0.690(0.529–0.899)***

Birth order

1st

1

1

2nd

0.991(0.944–1.040)

0.992(0.945–1.041)

3rd

0.917(0.859–0.979)***

0.917(0.859–0.979)***

4th or higher

0.905(0.840–0.975)***

0.904(0.839–0.973)***

Size-at-birth

Small

1

1

Average

0.996(0.964–1.029)

0.994(0.963–1.027)

Large

1.013(0.978–1.048)

1.016(0.981–1.051)

Birth Interval

^≤2.5 years

1

1

>  2.5 years

0.964(0.928–1.002)*

0.964(0.928–1.001)*

Skilled birth attendant

No

1

1

Yes

1.185(1.117–1.258)***

1.165(1.097–1.237)***

Had at least one vaccination

No

1

1

Yes

1.356(1.247–1.474)***

1.351(1.244–1.468)***

Age at birth (years)

<  20

1

1

20–24

1.158(1.062–1.263)***

1.141(1.046–1.245)***

25–29

1.258(1.138–1.391)***

1.230(1.113–1.360)***

30–34

1.307(1.170–1.460)***

1.273(1.140–1.423)***

35 and above

1.284(1.134–1.454)***

1.248(1.103–1.413)***

Education level

None

1

1

Primary

1.131(0.985–1.299)*

1.111(0.968–1.274)

Secondary

1.181(1.083–1.288)***

1.164(1.068–1.269)***

Tertiary

1.330(1.203–1.470)***

1.300(1.177–1.436)***

Had at least 1 prenatal visit

No

1

1

Yes

1.407(1.268–1.562)***

1.355(1.223–1.503)***

Polygynous

No

1

1

Yes

0.929(0.867–0.994)**

0.950(0.887–1.018)

Occupation

Low skill

0.938(0.844–1.044)

1.007(0.906–1.119)

Medium skill

1.039(0.992–1.088)

1.015(0.969–1.063)

High skill

1.020(0.951–1.095)

0.995(0.929–1.067)

Other

1

1

Decision maker

No

1

1

Yes

1.006(0.949–1.067)

1.007(0.950–1.067)

Access to media

No

1

1

Yes

1.062(0.991–1.137)*

1.055(0.986–1.130)

Lost 2+ children

No

1

1

Yes

0.932(0.880–0.988)**

0.942(0.889–0.998)**

Age (years)

<  25

1

1

25–34

1.017(0.828–1.249)

1.015(0.828–1.244)

35–44

1.048(0.849–1.293)

1.041(0.845–1.284)

45–54

1.058(0.850–1.316)

1.045(0.840–1.300)

55 and above

1.037(0.821–1.309)

1.016(0.805–1.283)

Education level

None

1

1

Primary

1.026(0.827–1.274)

1.021(0.824–1.266)

Secondary

1.258(1.140–1.387)***

1.248(1.133–1.376)***

Tertiary

1.296(1.177–1.428)***

1.280(1.164–1.408)***

Occupation

Low skill

0.916(0.867–0.966)***

0.937(0.888–0.988)**

Medium skill

1.007(0.960–1.056)

0.995(0.949–1.043)

High skill

1.044(0.987–1.104)

1.047(0.990–1.107)

Other

1

1

Owns a bank account

No

1

1

Yes

1.184(1.111–1.262)***

1.185(1.112–1.263)***

Wealth status

Poor

1

1

Average

1.536(1.368–1.724)***

1.317(1.164–1.490)***

Rich

1.906(1.695–2.142)***

1.497(1.307–1.714)***

Religion

Islam

1

1

Christian

1.109(0.993–1.238)*

1.117(1.002–1.246)***

Other

0.790(0.643–0.971)**

0.807(0.659–0.988)**

Ethnicity

Hausa/Fulani

1

1

Igbo

0.987(0.919–1.060)

1.042(0.958–1.133)

Yoruba

1.133(1.064–1.208)***

1.089(1.005–1.179)**

Other

0.938(0.893–0.986)**

0.945(0.892–1.001)*

Location of residence

Rural

1

1

Urban

1.137(1.081–1.197)***

1.037(0.987–1.091)

Distance to registration centres

< 5 kms

1

1

5–9.99 kms

0.764(0.666–0.877)***

0.869(0.761–0.992)**

10+ kms

0.465(0.392–0.552)***

0.563(0.479–0.662)***

Distance to roads

< 5 kms

1

1

5–9.99 kms

1.099(0.969–1.247)

1.095(0.973–1.232)

10+ kms

0.938(0.814–1.081)

0.986(0.867–1.122)

Altitude

Low

1

1

Medium

1.042(0.916–1.186)

1.042(0.925–1.173)

High

1.508(1.308–1.739)***

1.374(1.202–1.571)***

Average wealth status

Non-Poor

1

1

Poor

0.385(0.332–0.446)***

0.678(0.573–0.802)***

Child mortality

No

1

1

Yes

0.785(0.697–0.883)***

0.916(0.822–1.022)

Region

North Central

0.962(0.873–1.062)

0.966(0.884–1.056)

North East

1.127(0.980–1.296)*

1.391(1.224–1.582)***

North West

1

1

South East

0.916(0.797–1.051)

0.768(0.664–0.888)***

South South

1.016(0.906–1.139)

0.914(0.819–1.020)

South West

1.283(1.172–1.404)***

1.010(0.910–1.121)

Constant

0.105(0.098–0.113)***

0.035(0.019–0.062)***

0.251(0.162–0.389)***

0.064(0.036–0.115)***