Urinary Polycyclic Aromatic Hydrocarbon Metabolites and Attention/Deficit Hyperactivity Disorder, Learning Disability, and Special Education in U.S. Children Aged 6 to 15
Table 2
Descriptive characteristics by ADHD, LD, and SE, NHANES 2001–2004 participants aged 6–15 with no missing covariates or outcomes ()a.
Characteristic
Ever diagnosed with ADHD
Ever diagnosed with LD
Receiving SE
Yes
No
Yes
No
Yes
No
()b
()b
()b
()b
()b
()b
Age (years)
0.017
Sex
0.002
0.002
0.003
Male
58 (5.3)
550 (44.3)
89 (7.6)
519 (42.0)
84 (7.0)
524 (42.6)
Female
25 (2.2)
624 (48.2)
57 (4.2)
592 (46.2)
45 (3.7)
604 (46.7)
Race/ethnicity
0.545
0.019
0.06
White
31 (5.1)
319 (56.1)
46 (7.9)
304 (53.4)
41 (7.1)
309 (54.1)
Black
29 (1.0)
409 (14.3)
64 (2.3)
374 (13.1)
53 (2.0)
385 (13.4)
Hispanic
21 (1.2)
410 (17.2)
35 (1.5)
396 (16.9)
34 (1.4)
397 (17.0)
Other
2 (0.2)
36 (4.8)
1 (0.2)
37 (4.9)
37 (4.9)
1 (0.2)
Birthweight
0.584
0.003
<0.001
≥5.5 lbs
69 (6.5)
1018 (82.4)
115 (9.5)
972 (79.4)
97 (8.2)
990 (80.8)
<5.5 lbs
14 (1.0)
156 (10.0)
31 (2.3)
139 (8.7)
32 (2.5)
138 (8.6)
Received newborn care at health facility
0.912
0.386
0.645
Yes
12 (1.0)
145 (12.1)
26 (1.9)
131 (11.2)
23 (1.6)
134 (11.5)
No
71 (6.6)
1029 (80.3)
120 (9.9)
980 (77.0)
106 (9.1)
994 (77.8)
Maternal age at birth (years)
0.169
Maternal smoking during pregnancy
0.007
<0.001
<0.001
Yes
27 (2.9)
173 (18.1)
43 (4.6)
157 (16.4)
44 (4.6)
156 (16.5)
No
56 (4.7)
1001 (74.3)
103 (7.2)
954 (71.8)
85 (6.1)
972 (72.9)
Smoker(s) in household
0.013
<0.001
0.003
Yes
26 (2.9)
242 (19.8)
54 (4.7)
214 (18.0)
43 (4.0)
225 (18.7)
No
57 (4.6)
932 (72.7)
92 (7.1)
897 (70.2)
86 (6.7)
903 (70.6)
Has routine source of care
0.691
0.485
<0.001
Yes
81 (7.2)
1071 (87.1)
138 (11.3)
1014 (83.0)
126 (10.6)
1026 (83.7)
No
2 (0.3)
81 (7.2)
8 (0.5)
97 (5.2)
3 (0.1)
102 (5.6)
Health insurance coverage
0.221
0.787
0.097
Yes
77 (7.0)
981 (80.5)
129 (10.4)
929 (77.0)
118 (9.8)
940 (77.6)
No
6 (0.6)
193 (12.0)
17 (1.4)
182 (11.2)
11 (0.8)
188 (11.7)
BMI
0.668
0.255
0.365
<25
70 (6.6)
944 (78.0)
108 (9.3)
906 (75.3)
101 (8.7)
913 (75.9)
25–30
9 (0.5)
152 (9.8)
23 (1.6)
138 (8.7)
17 (1.1)
144 (9.2)
>30
4 (4.7)
78 (4.7)
15 (0.9)
67 (4.2)
11 (0.9)
71 (4.2)
Ever attended preschool
0.695
0.654
0.735
Yes
66 (5.4)
778 (64.1)
104 (8.5)
740 (61.1)
91 (7.6)
753 (61.9)
No
17 (2.1)
396 (28.3)
42 (3.4)
371 (27.1)
38 (3.1)
375 (27.4)
PIR
0.113
0.008
0.028
<1
26 (2.8)
392 (20.3)
64 (4.6)
354 (19.0)
57 (4.1)
361 (19.5)
1–1.84
18 (1.3)
266 (17.8)
32 (2.2)
252 (17.0)
25 (1.6)
259 (17.6)
1.85–3
17 (1.1)
218 (19.1)
28 (2.3)
207 (17.9)
26 (2.3)
209 (17.9)
>3
22 (2.3)
298 (34.7)
22 (2.7)
298 (34.3)
21 (2.7)
299 (34.3)
Creatinine mg/dL (log-transformed)
0.4
0.809
Fasting time hr (log-transformed)
0.316
0.037
1-Pyrene ng/L (log-transformed)
0.591
0.288
1-Pyrene
0.785
0.819
0.087
High
46 (4.0)
580 (46.1)
76 (6.1)
550 (44.0)
74 (6.5)
552 (43.6)
Low
37 (3.6)
594 (46.3)
70 (5.8)
561 (44.1)
55 (4.2)
576 (45.7)
0.702
0.25
0.335
1-Napthol
0.645
0.024
0.146
High
42 (3.6)
610 (46.4)
90 (7.1)
562 (42.9)
74 (6.1)
578 (44.0)
Low
41 (3.9)
564 (46.0)
56 (4.7)
549 (45.3)
55 (4.6)
550 (45.4)
2-Napthol ng/L (log-transformed)
0.14
0.856
0.16
2-Napthol
0.082
0.384
0.693
High
40 (2.9)
655 (47.2)
80 (5.3)
615 (44.8)
69 (5.6)
626 (44.5)
Low
43 (4.7)
519 (45.3)
66 (6.5)
496 (43.4)
60 (5.1)
502 (44.8)
Table values are mean ± SD for continuous variables and (%) for categorical variables.
bPercentages may not sum to 100% due to rounding.
c value is for -test (continuous variables) or χ 2 test (categorical variables).
