Table 1.
Selection, enrollment, and initial and final exposure status of study subjects
| Initial Exposure Status | ||||
|---|---|---|---|---|
| Index Subject | Older Sibling | |||
| Exposed | Unexposed | Unexposed | Total | |
| Selected | 1910 | 1928 | 1202 | 5040 |
| Excluded during enrollment | ||||
| Deceased | 35 | 40 | 36 | 111 |
| Parent refused participation | 199 | 148 | 80 | 427 |
| Never located | 113 | 149 | 70 | 332 |
| No response | 871 | 887 | 536 | 2294 |
| Refused | 73 | 78 | 36 | 187 |
| Returned questionnaire | 619 | 626 | 444 | 1689 |
| Percent of selected | 32.4% | 32.5% | 36.9% | 33.5% |
| Percent of located | 39.6% | 39.3% | 43.7% | 40.5% |
| Excluded during exposure assessment | ||||
| Inadequate residential history | 15 | 37 | 29 | 81 |
| Off-Cape address in potential VL/AC town |
19 | 27 | 50 | 96 |
| Available for analysis | 585 | 562 | 365 | 1512 |
| Percent of selected | 30.6% | 29.1% | 30.4% | 30.0% |
| Final exposure status | ||||
| Both prenatal and early childhood exposure |
561 | 160 | 110 | 831 |
| Only early childhood exposure |
7 | 42 | 85 | 134 |
| Unexposed | 17 | 360 | 170 | 547 |