Table 3 The combined effects of 5mdC, total urinary arsenic, and blood lead levels on with developmental delay in preschool children

≤ 12.55

≤ 3.00

10/26

1.00^§,a,***

1.00^§,c,***

>12.55

≤ 3.00

22/18

2.22 (0.75 – 6.55)

1.26 (0.36 – 4.42)

≤ 12.55

>3.00

61/18

8.06 (3.12 – 20.78)^***

4.89 (1.69 – 14.21)^**

>12.55

>3.00

84/26

7.56 (2.90 – 19.76)^***

4.27 (1.48 – 12.27)^**

Synergy index

0.79 (0.34 – 1.84)

0.79 (0.27 – 2.33)

p interaction 

0.2047

0.097

5mdC (%)

Total urinary arsenic(μg/L)

>5.03

≤ 12.55

9/23

1.00^§,a,***

1.00^§,c,***

>5.03

>12.55

15/21

1.29 (0.38 – 4.33)

1.21 (0.30 – 4.91)

≤ 5.03

≤ 12.55

62/21

7.12 (2.73 – 18.55)^***

8.18 (2.64 – 25.31)^**

≤ 5.03

>12.55

88/23

8.55 (3.07 – 23.81)^***

8.09 (2.49 – 26.34)^**

Synergy index

1.18 (0.49 – 2.84)

0.96 (0.35 – 2.60)

p interaction 

0.6872

0.7160

5mdC (%)

Blood lead(μg/dL)

>5.03

≤ 3.00

0/25

1.00^§,***

1.00^§,***

>5.03

>3.00

24/19

≤ 5.03

≤ 3.00

32/19

3.00 (1.35 – 6.67)^**

4.00 (1.53 – 10.49)^**

≤ 5.03

>3.00

118/25

9.63 (4.77 – 19.47)^***

9.51 (4.18 – 21.64)^***

p interaction 

0.011

0.021

5mdC (%)

Total urinary arsenic(μg/L)

Blood lead(μg/L)

Children with /without developmental delay

Age-sex-adjusted ORs (95% CI)^a

Multivariate ORs(95% CI)^c

>5.03

≤ 12.55

≤ 3.00

0/16

1.00^§,***

1.00^§,***

>5.03

>12.55

≤ 3.00

9/16

>5.03

> 12.55

>3.00

15/12

4.26 (1.33 – 13.66)^*

3.46 (0.90 – 13.37)⁺

≤ 5.03

≤ 12.55

≤ 3.00

10/10

3.63 (1.07 – 12.33)^*

7.87 (1.78 – 34.83)^**

≤ 5.03

>12.55

≤ 3.00

74/20

12.48 (4.94 – 31.57)^***

10.78 (3.64 – 31.87)^***

≤ 5.03

> 12.55

>3.00

66/14

20.11 (7.18 – 56.35)^***

18.82 (5.72 – 61.85)^***