Table 1.
Demographic characteristics of study population.
| Preschool ADHD | MoBa controls | |||
|---|---|---|---|---|
| N = 260 | N = 549 | |||
| N or Mean | % or SDa | N or Mean | % or SDa | |
| Child sex | ||||
| Male | 145 | 56% | 275 | 50% |
| Female | 115 | 44% | 274 | 50% |
| Child age at clinical assessment (months) | 41.6 | 1.2 | ||
| Maternal age at delivery (years)b | 30.0 | 4.1 | 30.9 | 4.2 |
| ≤25 | 32 | 12% | 46 | 8% |
| 26–30 | 111 | 43% | 206 | 38% |
| 31–35 | 99 | 38% | 218 | 40% |
| >35 | 18 | 7% | 77 | 14% |
| Missing | 2 | |||
| Maternal educationb | ||||
| <College completed | 92 | 36% | 121 | 22% |
| College completed | 108 | 42% | 237 | 44% |
| >College completed | 59 | 23% | 184 | 34% |
| Missing | 1 | 7 | ||
| Marital statusb | ||||
| Married | 113 | 44% | 287 | 53% |
| Cohabitating | 131 | 51% | 244 | 45% |
| Other | 15 | 6% | 13 | 2% |
| Missing | 1 | 5 | ||
| Primiparousb | 156 | 60% | 270 | 49% |
| Missing | 2 | |||
| Self-reported smoking during pregnancyb | 62 | 24% | 76 | 14% |
| Missing | 1 | 6 | ||
| Maternal self-reported symptoms during pregnancy | ||||
| Significant symptoms of depressionb,c | 42 | 16% | 34 | 6% |
| Missing | 5 | 14 | ||
| Significant ADHD-like symptomsb,d | 33 | 13% | 21 | 4% |
| Missing | 2 | 12 | ||
aPercentages may not add to 100% due to rounding.
bComparing reference population to all cases, significant (P < 0.05) using t-test for continuous variables, chi-squared test for categorical variables, or Fisher’s exact test for categorical variables with sparse cells.
cMean score ≥2 indicative of presence of depression.
dScores ≥4 indicative of ADHD-like symptoms.