Table 1.
Demographics of the ABCD cohort.
| Release 2.0 (%) | Sample with Complete Data Used in This Study (%) | ACS Target | |
|---|---|---|---|
| Sex | |||
| Male | 6,188 (52.1%) | 5,106 (52.6%) | N/A* |
| Female | 5,681 (47.8%) | 4,606 (47.4%) | N/A* |
| Missing/Undefined | 6 (0.1%) | 0 (0%) | -- |
| Income Bracket | |||
| <$50K (Low) | 3,222 (27.1%) | 2,825 (29.1%) | 39% |
| $50–100K (Mid) | 3,070 (25.9%) | 2,783 (28.7%) | 30% |
| >$100K (High) | 4,565 (38.4%) | 4,104 (42.3%) | 31% |
| Missing/Undefined | 1,018 (8.6%) | 0 (0%) | -- |
| Lead Risk | |||
| Low (1–3) | 4,373 (36.8%) | 3,967 (40.8%) | N/A |
| Intermediate (4–7) | 3,544 (29.8%) | 3,088 (31.8%) | N/A |
| High (8–10) | 3,258 (27.4%) | 2,657 (27.4%) | N/A |
| Missing/Undefined | 700 (5.9%) | 0 (0%) | -- |
| Race/Ethnicity | |||
| Asian | 252 (2.1%) | 188 (1.9%) | 5% |
| Black | 1,779 (15.0%) | 1279 (13.2%) | 17% |
| Hispanic | 2,407 (20.3%) | 1881 (19.4%) | 23% |
| Other | 1,245 (10.5%) | 1012 (10.4%) | 5% |
| White | 6,174 (52.0%) | 5352 (55.1%) | 49% |
| Missing/Undefined | 18 (0.2%) | 0 (0%) | -- |
| Total | 11,875 | 9,712 | 100% |
Lead risk was categorized as being either low (lead risk ≤ 3), intermediate (4 ≤ lead risk ≤ 7) or high (lead risk ≥ 8) (Figure 1). The targeted percentages at each level of the demographics were based on the American Community Survey (ACS).
*
While there were no explicit targets for sex, it was generally assumed the ABCD sample would be split evenly between sexes. Recruitment was consistently monitored for any critical deviations from this assumption.