Table 5 Results of multivariable parametric Gompertz distribution country-level shared frailty survival regression model among infants in SSA countries, 2020

Infant sex

Male

36,795

11,676

1

1

Female

36,105

9189

0.82 (0.80–0.84)

0.86 (0.83–0.89) ***

Plurality

Single

70,550

18,055

1

1

Multiple

2350

2810

3.47 (3.34–3.62)

2.68 (2.54–2.82) ***

Birth size at birth

Average

32,279

7031

1

1

Smaller than average

12,449

4472

1.61 (1.55–1.67)

1.28 (1.22–1.34) ***

Larger than average

25,015

5341

0.95 (0.91–0.98)

0.95 (0.91–0.99) *

Immediately breastfeed

No

38,106

18,172

1

1

Yes

34,794

2693

0.18 (0.17–0.19)

0.24 (0.23–0.25) ***

Teenage pregnancy

≥ 20 years

61,623

16,613

1

1

<  19 years

11,277

4252

1.31 (1.27–1.36)

1.19 (1.10–1.29) ***

Birth interval

≥ 24 months

49,008

10,472

1

1

18–23 months

5732

2854

2.02 (1.94–2.12)

1.93 (1.83–2.02) ***

<  18 months

2363

2485

3.57 (3.41–3.73)

3.27 (3.10–3.45) ***

Birth order

≤ Three

41,166

11,036

1

1

≥ Four

31,734

9829

1.10 (1.07–1.13)

1.14 (1.10–1.19) ***

Place of delivery

Health facility

47,266

10,150

1

1

Home

25,624

7909

1.31 (1.27–1.35)

1.08 (1.04–1.13) **

Mode of delivery

SVD

69,097

19,883

1

1

Cesarean section

3803

982

1.02 (0.96–1.09)

1.02 (0.94–1.12)

Mother education

No education

29,303

10,260

1

1

Primary

24,126

6476

0.91 (0.88–0.95)

0.99 (0.94–1.04)

Secondary & above

19,471

4129

0.69 (0.66–0.72)

0.88 (0.82–0.95) ***

Father education

No education

22,966

8240

1

Primary

16,988

4654

0.91 (0.87–0.95)

0.95 (0.90–0.99) **

Secondary & above

21,475

5188

0.75 (0.72–0.78)

0.90 (0.85–0.96) ***

Residence

Urban

21,998

5526

1

1

Rural

50,902

15,339

1.15 (1.11–1.18)

1.04 (0.98–1. 09)

Wealth index

Poor

34,814

10,669

1

1

Middle

14,313

4201

0.94 (0.91–0.97)

1.03 (0.96–1.07)

Rich

23,773

5995

0.82 (0.80–0.85)

1.04 (0.98–1.10)

Latrine facility

Had latrine

47,865

13,240

1

1

No latrine

25,033

7623

1.10 (1.07–1.14)

1.04 (0.99–1.09)

Water source

Improved

16,954

3845

1

1

Not improved

55,946

17,020

1.16 (1.11–1.20)

1.07 (1.01–1.13) *

Country income

Low income

42,743

12,842

1

1

Lower middle income

27,115

7433

0.87 (0.71–1.01)

0.96 (0.80–1.17)

Higher middle income

3042

590

0.70 (0.48–1.02)

1.12 (0.79–1.59)

−0.06 (−0.07 – −0.05)

0.06 (0.04–0.11) ***

0.03 (0.02–0.05)