Table 1.

Characteristics of New Bedford Cohort participants who were included in the main analysis group ¹ and those who were not included in the main analysis.

Descriptive Characteristic	NBC Participants Included in Main Analysis, n = 373			NBC Participants not Included in Main Analysis, n = 415
Inhibition Measures 2	n (%)	Mean (SD)	Range	n (%)	Mean (SD)	Range	p -Value 3
Design Fluency
Total number correct scaled score	373	9.6 (2.7)	2–17	155	9.3 (3)	1–19	0.3
Total number errors raw score	373	2.2 (2.7)	0–19	155	2.6 (3.5)	0–30	0.1
Color–Word Interference scores
Completion time scaled score	373	9.9 (2.8)	1–16	154	9.8 (2.7)	1–14	0.6
Total number errors raw score	373	2.3 (2.5)	0–19	154	2.3 (2.3)	0–12	0.7
Overall performance
Best performance	117 (31.4)			37 (8.9)			0.1
Poor performance	256 (68.6)			117 (28.2)
Missing	0			261 (62.9)
Exposure Measures 4
Cord serum DDE (ng/g)	373	0.6 (1.2)	0.02–14.9	378	0.4 (0.4)	0.0–4.2	<0.01 *
Cord serum HCB (ng/g)	373	0.03 (0.02)	0.0–0.1	378	0.03 (0.05)	0.0–0.7	0.1
Cord serum ΣPCB4 (ng/g)	373	0.3 (0.3)	0.01–4.4	378	0.2 (0.2)	0.01–1.9	0.05
Cord blood Pb (μg/dL)	373	1.4 (0.9)	0–9.4	375	1.7 (1.7)	0.0–17.4	<0.01 *
Cord blood Mn (µg/dL)	373	4.2 (1.6)	0.7–14.6	335	4.3 (2.0)	0.2–22.1	0.6
Covariate Measures 5
Child Characteristics
Race/Ethnicity							0.09
Non-Hispanic White	263 (70.5)			268 (64.6)
Hispanic	33 (8.8)			56 (13.5)
Other	77 (20.6)			89 (21.4)
Missing	0			2 (0.5)
Sex							0.05
Male	179 (48.0)			229 (55.2)
Female	194 (52.0)			186 (44.8)
Age at Exam	373	15.5 (0.6)	14.4–17.8	155	15.7 (0.7)	13.9–17.9	<0.01 *
Home Score	373	43.9 (6.3)	21–56	118	42.7 (6.0)	27–53	0.07
Year of birth
1993–1994	100 (26.8)			159 (38.3)			<0.01 *
1995–1996	153 (41.0)			147 (35.4)
1997–1998	120 (32.2)			109 (26.3)
Maternal Characteristics
Marital status at birth							<0.01 *
Not married	136 (36.5)			195 (47.0)
Married	237 (63.5)			165 (39.8)
Missing	0			55 (13.3)
Maternal IQ	373	99.4 (10.4)	57–124	262	95.8 (10.2)	72–126	<0.01 *
Seafood during pregnancy (serv/day)	373	0.5 (0.6)	0–5.3	260	0.6 (0.7)	0–6	0.6
Smoking during pregnancy							0.1
No	272 (72.9)			210 (50.6)
Yes	101 (27.1)			103 (24.8)
Missing	0			102 (24.6)
Household Characteristics at Birth
Maternal education							<0.01 *
≤High School	190 (50.9)			231 (55.7)
>High School	183 (49.1)			127 (30.6)
Missing	0			57 (13.7)
Paternal Education							<0.01 *
≤High School	246 (66.0)			266 (64.1)
>High School	127 (34.0)			81 (19.5)
Missing	0			68 (16.4)
Annual Household Income							<0.01 *
<USD 20,000	115 (30.8)			150 (36.1)
≥USD 20,000	258 (69.2)			201 (48.4)
Missing	0			64 (15.4)
Examination Characteristics
Examiner							0.4
1	277 (74.3)			121 (29.2)
2	96 (25.7)			34 (8.2)
Missing	0			260 (62.7)

¹ Main analysis group (Set 1): complete inhibition outcome, covariate, and exposure data for, DDE, HCB, ΣPCB₄, Pb and Mn, n = 373. ² NBC participants with missing inhibition measures: Design Fluency total correct n = 260, total errors n = 260; Color–Word Interference completion time n = 261, total errors n = 261.³ P-values represent results comparing characteristics between participants included in Set 1 and those excluded from Set 1 using t-tests, Wilcoxon rank sum tests, and chi-square tests. P-values reflect comparisons based on non-missing data. ⁴ NBC participants with missing exposure measures: DDE n = 37; HCB n = 37; ΣPCB₄ n = 37; Pb n= 40; Mn n = 80. ⁵ NBC participants with missing covariate measures: age at exam n = 260; HOME score n= 297; maternal IQ n = 153; seafood during pregnancy n= 155. * p < 0.05. Abbreviations: DDE: dichlorodiphenyldichloroethylene; HCB: hexachlorobenzene; ΣPCB₄: sum of 4 PCB congeners (118, 138, 153, 180); Pb: lead; Mn: manganese.