Table 2 Cox’s proportional hazards model and frailty model analysis: risk factors of child mortality in Bangladesh (BDHS, 2007–2014)

Age at marriage (≥ 18 years)

< 18 years

1.13

0.94–1.35

1.13

0.94–1.35

1.13

0.94–1.36

Religion (Muslim)

Other

1.01

0.8–1.28

1.00

0.79–1.27

1.00

0.79–1.27

Sex of children (Male)

Female

0.86^b

0.75–0.98

0.86^b

0.75–0.98

0.85^b

0.75–0.98

Age at child birth (<25 years)

25–34 years

0.82^c

0.67–1.02

0.83^c

0.67–1.02

0.83^c

0.67–1.03

≥35 years

0.95

0.65–1.39

0.95

0.65–1.4

0.96

0.65–1.43

Maternal education (No education)

Primary

0.87

0.73–1.05

0.87

0.73–1.05

0.87

0.72–1.06

Secondary or higher

0.73^a

0.59–0.90

0.73^a

0.59–0.90

0.73^a

0.58–0.90

Paternal education (No education)

Primary

0.96

0.81–1.14

0.96

0.81–1.14

0.96

0.81–1.14

Secondary or higher

0.73^a

0.59–0.89

0.73^a

0.59–0.89

0.72^a

0.59–0.89

PBI and Birth order (First)

Short and 2–4

1.18

0.94–1.48

1.16

0.93–1.46

1.05

0.84–1.33

Short and 5+

1.69^a

1.16–2.46

1.67^a

1.14–2.44

1.56^b

1.06–2.31

Medium and 2–4

0.67^a

0.54–0.82

0.67^a

0.54–0.82

0.65^a

0.53–0.80

Medium and 5+

0.55^a

0.35–0.85

0.54^a

0.35–0.84

0.53^a

0.34–0.82

Large and 2–4

0.64^a

0.51–0.79

0.64^a

0.51–0.80

0.63^a

0.50–0.79

Large and 5+

0.88

0.58–1.33

0.88

0.57–1.33

0.86

0.56–1.32

Wealth index (Poor)

Middle

1.01

0.84–1.22

1.01

0.83–1.22

1.01

0.84–1.23

Rich

0.97

0.79–1.19

0.97

0.79–1.19

0.97

0.79–1.19

Exposure to media (No)

Yes

1.00

0.85–1.17

1.01

0.86–1.18

1.00

0.85–1.18

Maternal malnutrition (Normal)

Underweight

0.88^c

0.75–1.02

0.87^c

0.75–1.02

0.87^c

0.74–1.02

Overweight or obese

1.08

0.86–1.35

1.08

0.87–1.36

1.09

0.86–1.37

Maternal working status (No)

Yes

1.23^b

1.05–1.45

1.24^b

1.05–1.46

1.24^b

1.05–1.47

Place of residence (Urban)

Rural

1.01

0.86–1.19

1.01

0.86–1.2

1.01

0.86–1.19

Paternal age (≤25 years)

26–35 years

0.78^b

0.64–0.96

0.79^b

0.64–0.96

0.79^b

0.64–0.97

≥35 years

0.68^a

0.53–0.88

0.68^a

0.53–0.88

0.69^a

0.53–0.89

Division (Barishal)

Chittagong

1.04

0.8–1.34

1.03

0.79–1.34

1.03

0.79–1.34

Dhaka

0.92

0.71–1.2

0.92

0.7–1.2

0.92

0.7–1.21

Khulna

0.90

0.67–1.22

0.90

0.66–1.22

0.89

0.66–1.22

Rajshahi

1.01

0.78–1.30

1.00

0.77–1.30

1.00

0.78–1.30

Sylhet

1.53^a

1.19–1.96

1.51^a

1.17–1.96

1.53^a

1.19–1.98

Survey year (2007)

2011

0.85^b

0.73–1.01

0.86^c

0.72–1.01

0.85^c

0.72–1.01

2014

0.75^a

0.64–0.9

0.76^a

0.63–0.90

0.76^a

0.64–0.90

Variance of frailty

–

0.1066

0.5734

Kendall’s τ

–

0.0506

0.2228

MHR

–

1.3719

2.1907

Log–likelihood

-8652

-8561

-8151