Table 3 Incident rate ratios (IRR) from zero-inflated negative binomial regression

Age group

 15–19 (ref)

 20–29

1.09

1.03–1.16

0.003

 31–49

1.15

1.05–1.25

0.001

Division

 Barisal (ref)

 Chittagong

0.88

0.81–0.95

< 0.001

 Dhaka

1.01

0.93–1.09

0.797

 Khulna

1.11

1.02–1.21

0.011

 Mymensingh

1.07

0.99–1.17

0.087

 Rajshahi

1.04

0.95–1.13

0.402

 Rangpur

1.21

1.11–1.31

< 0.001

 Sylhet

0.92

0.84–1.00

0.051

Place of residence

 Urban (ref)

 Rural

0.88

0.84–0.92

< 0.001

Wealth index

 Poor (ref)

 Middle

1.07

1.01–1.13

0.026

 Rich

1.14

1.08–1.21

< 0.001

Educational level

 No education (ref)

 Primary

1.13

1.02–1.27

0.023

 Secondary

1.27

1.14–1.42

< 0.001

 Higher

1.34

1.18–1.51

< 0.001

Birth order

 1 (ref)

 2–3

0.95

0.90–1.00

0.034

 4 +

0.84

0.76–0.92

< 0.001

Age at first birth

 Before 18 (ref)

 18–25

0.96

0.92–1.01

0.105

 26 +

1.01

0.91–1.12

0.814

Pregnancy wanted

 Then (ref)

 Later

0.91

0.86–0.96

< 0.001

 No more

0.83

0.77–0.91

< 0.001

Number of household members

 1–5 (ref)

 6–10

0.99

0.95–1.03

0.585

 11 +

0.99

0.92–1.07

0.808

Husband’s educational level

 No education (ref)

 Primary

1.03

0.96–1.10

0.464

 Secondary

1.13

1.05–1.21

0.001

 Higher

1.25

1.15–1.36

< 0.001

Husband’s occupation

 Unemployed (ref)

 Agricultural or household work

1.11

0.89–1.38

0.363

 Service and sales

1.18

0.95–1.47

0.129

 Others

1.16

0.93–1.44

0.183

Media coverage

 No (ref)

 Yes

1.19

1.14–1.25

< 0.001