Table 2 Child and family characteristics associated with hospital visit for maltreatment-related injury in infancy (n = 2,206,441)

Birth year (Ref: 2004–2009)

 2010–2014

1.18 (1.00, 1.39)^*

0.98 (0.72, 1.33)

1.66 (1.57, 1.75)^***

Age (Ref: 8–11 months old)

 4–7

1.57 (1.26, 1.96)^***

0.80 (0.57, 1.11)

2.61 (2.38, 2.86)^***

 0–3

2.00 (1.62, 2.47)^***

0.39 (0.25, 0.58)^***

5.39 (4.96, 5.86)^***

Gender (Ref: Female)

 Male

1.36 (1.16, 1.61)^***

1.29 (0.95, 1.74)

0.99 (0.94, 1.05)

Birthweight (Ref: ≥2500 g)^a

 2000–2499

1.83 (1.40, 2.39)^***

0.81 (0.40, 1.66)

1.10 (0.98, 1.23)

 <2000

4.08 (2.93, 5.68)^***

2.33 (1.03, 5.30)^*

1.98 (1.69, 2.31)^***

Maternal marital status (Ref: Married)^b

 Single

2.68 (2.08, 3.45)^***

1.36 (0.72, 2.58)

1.16 (1.01, 1.34)^*

 Others (divorced, widowed)

2.40 (1.74, 3.32)^***

0.91 (0.33, 2.51)

0.87 (0.68, 1.11)

 Missing

0.47 (0.32, 0.69)^***

0.48 (0.24, 0.95)^*

1.00 (0.88, 1.13)

Having at least one older child (Ref: No) ^c,d

 Yes

1.32 (1.10, 1.58)^**

0.96 (0.68, 1.35)

0.88 (0.83, 0.94)^***

Income level (insurance status) (Ref: Low income/poverty) ^c

 Middle income

0.56 (0.47, 0.67)^***

1.02 (0.72, 1.44)

1.12 (1.04, 1.21)^**

 High income

0.55 (0.42, 0.72)^***

0.47 (0.28, 0.80)^**

2.05 (1.89, 2.23)^***

Maternal educational attainment (Ref: College or above)^a

 Senior high school

1.73 (1.39, 2.14)^***

1.03 (0.72, 1.47)

0.59 (0.55, 0.63)^***

 Junior high school or below

2.76 (2.16, 3.52)^***

1.64 (1.05, 2.55)^*

0.47 (0.42, 0.52)^***

Maternal age at having the index child (Ref: 35 years old or above)^a

 20–34

0.98 (0.77, 1.24)

1.55 (0.93, 2.57)

0.70 (0.66, 0.75)^***

 <20

1.61 (1.08, 2.40)^*

1.35 (0.47, 3.87)

0.36 (0.24, 0.54)^***

Maternal depression (Ref: No) ^c,e

 Yes

1.57 (1.08, 2.27)^*

1.36 (0.60, 3.09)

1.06 (0.89, 1.27)

Maternal substance use problems (Ref: No)^c,e

 Yes

2.42 (1.45, 4.04)^***

0.78 (0.11, 5.61)

0.82 (0.53, 1.26)