Table 1. Characteristics of Participants in the Boston Birth Cohort, 1998-2019.
| Characteristic | No. (%) | |
|---|---|---|
| No ADHD diagnosis | ADHD diagnosis | |
| Total participants, No. | 2652 | 486 |
| Maternal age, median (IQR), y | 26.7 (22.5-33.3) | 28.4 (23.4-33.4) |
| Maternal race and ethnicity | ||
| Asian (non-Pacific Islander) | 44 (1.7) | 2 (0.4) |
| Hispanic | 589 (22.2) | 112 (23.0) |
| Non-Hispanic Black | 1541 (58.1) | 297 (61.1) |
| Non-Hispanic White | 194 (7.3) | 33 (6.8) |
| Othera | 284 (10.7) | 42 (8.6) |
| Maternal marital status | ||
| Single | 1671 (63.0) | 344 (70.8) |
| Married | 913 (34.4) | 121 (24.9) |
| Otherb | 68 (2.6) | 21 (4.3) |
| Maternal educational level | ||
| No school or elementary school | 117 (4.4) | 15 (3.1) |
| Some secondary school | 631 (23.8) | 127 (26.1) |
| High school graduate | 946 (35.7) | 191 (39.3) |
| Some college | 581 (21.9) | 104 (21.4) |
| College graduate | 377 (14.2) | 49 (10.1) |
| Annual income, $ | ||
| <35 000 | 1221 (46.0) | 236 (48.6) |
| ≥35 000 | 1165 (43.9) | 192 (39.5) |
| Unknown | 266 (10.0) | 58 (11.9) |
| Maternal obesity status | ||
| Normal weight | 1130 (42.6) | 188 (38.7) |
| Underweight | 112 (4.2) | 22 (4.5) |
| Overweight | 680 (25.6) | 133 (27.4) |
| Obese | 589 (22.2) | 114 (23.5) |
| Unknown | 141 (5.3) | 29 (6.0) |
| BMI, median (IQR) | 25.1 (21.8-29.6) | 25.7 (22.3-30.0) |
| Previous births | ||
| 0 | 1516 (57.2) | 282 (58.0) |
| ≥1 | 1136 (42.8) | 204 (42.0) |
| Substance exposure | ||
| None | 2041 (77.0) | 338 (69.5) |
| Tobacco | 460 (17.3) | 120 (24.7) |
| Alcohol | 205 (7.7) | 48 (9.9) |
| Cannabis | 100 (3.8) | 23 (4.7) |
| Opioids | 49 (1.8) | 11 (2.3) |
| Child sex | ||
| Female | 1417 (53.4) | 138 (28.4) |
| Male | 1235 (46.6) | 348 (71.6) |
| Child postnatal care visits | ||
| <2 | 811 (30.6) | 128 (26.3) |
| 3-4 | 891 (33.6) | 179 (36.8) |
| ≥5 | 950 (35.8) | 179 (36.8) |
| Child gestational age at birth | ||
| Term | 1908 (71.9) | 332 (68.3) |
| Preterm | 744 (28.1) | 154 (31.7) |
| Child follow-up duration, median (IQR), y | 12 (9-15) | 8 (7-10) |
Abbreviations: ADHD, attention-deficit/hyperactivity disorder; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared).
a
Includes individuals who self-identified as American Indian or indigenous, Cape Verdean, Pacific Islander, multiracial, or unknown.
b
Includes separated, divorced, and widowed.