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Table 1 General characteristics of study population

From: Blood lead concentrations and attention deficit hyperactivity disorder in Korean children: a hospital-based case control study

 

Cases (n = 114)

Controls (n = 114)

p-value

 

n (%)

n (%)

 

Sex, male

83 (72.8)

81 (71.1)

0.77

Economic status

 Low (< $3000)

41 (36.3)

63 (55.8)

0.01

 Middle ($3000-$4000)

35 (31.0)

30 (26.5)

 

 High (> $4000)

37 (32.7)

20 (17.7)

 

Paternal education

  ≥ 13 years

60 (52.6)

93 (81.6)

<0.001

Maternal education

  ≥ 13 years

58 (51.3)

94 (82.5)

<0.001

Paternal smoking behavior

60 (52.6)

59 (51.8)

0.50

Maternal smoking behavior

4 (3.5)

1 (0.9)

0.19

 

Mean ± SD

Mean ± SD

 

Age (year)

8.79 ± 1.57

8.73 ± 1.65

0.77

Gestational age (week)

39.06 ± 1.89

39.12 ± 2.64

0.85

Birth weight (kg)

3.22 ± 0.59

3.30 ± 0.57

0.28

ADHD-Rating Scale

 Inattention

9.33 ± 5.74

3.81 ± 3.50

0.001

 Hyperactivity/impulsivity

6.48 ± 4.80

2.35 ± 2.67

0.001

 Total

15.82 ± 9.99

6.16 ± 5.65

0.001

Continuous Performance Test

 Omission errors

57.27 ± 18.49

47.53 ± 6.51

0.001

 Commission errors

57.36 ± 16.32

52.17 ± 13.76

0.005

 Response time

52.33 ± 12.65

51.19 ± 10.58

0.46

 Response time variability

53.68 ± 16.84

47.11 ± 8.64

0.001