Table 1 Exclusions of CHDS children from a 5-Year examination subset for organochlorine study

1

Mother is an unmarried minor or no interview completed

587

17.2

2

Blood was drawn prior to second trimester or after 3^rd trimester

177

5.2

3

Not a singleton birth

28

0.8

4

Raven or Peabody cognitive test score missing

60

1.8

5

Hearing tests were not done in both ears

146

4.3

6

Confounding anomalies present

21

0.6

7

Mother is deaf

2

0.1

8

Congenital rubella*

46

1.3

9

Mother took a drug containing iodine

86

2.5

10

Thyroid drugs were taken within 60 d of blood draw

7

0.2

11

Gestational age is less than 244 or greater than 351 days

99

2.9

12

No current address is available

468

13.7

13

Does not reside in 1 of 8 included counties

337

9.9

14

Only one sibling in family can be included; other siblings dropped

57

1.7