Table 2.
Participant data for samples that passed quality control (n = 325) vs. samples that did not pass quality control (n = 50) and p-values for test statistic comparing the two groups
| Variable | Did Not Pass | Passed | p |
|---|---|---|---|
| Sex (% male) | 66.0 | 56.6 | .223 |
| Age (mean years) | 22.9 | 23.3 | .480 |
| Ethnicity | |||
| White (%) | 90.0 | 86.1 | .654 |
| African American (%) | 2.0 | 2.8 | 1.000 |
| Latinx (%) | 2.0 | 3.4 | 1.000 |
| Other (%) | 6.0 | 7.7 | 1.000 |
| Current income z-score (mean) | −.09 | −.02 | .518 |
| Childhood income z-score (mean) | .10 | −.02 | .489 |
| Current stimulant medication use (% yes) | 26.0 | 32.6 | .416 |
| Childhood stimulant medication use (% yes) | 23.2 | 21.4 | .842 |
| Prenatal tobacco exposure (% yes) | 2.6 | 4.6 | 1.000 |
| Prenatal alcohol exposure (% yes) | 2.6 | 2.3 | 1.000 |
| Preterm birth (% preterm) | 2.3 | 7.8 | .335 |
| Childhood secondhand smoke exposure (% yes) | 31.8 | 24.8 | .356 |
| Family Environment Scale – Conflict score (mean) | 52.7 | 49.4 | .076 |
| Highest level maternal education | |||
| High School (%) | 20.4 | 14.8 | .371 |
| Some college or college degree (%) | 47.7 | 60.0 | .141 |
| Graduate degree (%) | 31.8 | 23.1 | .256 |
| Highest level paternal education | |||
| High School (%) | 13.6 | 20.4 | .413 |
| Some college or college degree (%) | 45.5 | 50.9 | .522 |
| Graduate degree (%) | 38.6 | 26.6 | .108 |
| ADHD diagnosis (% yes) | 51.0 | 69.9 | .013 |
| ADHD persistence (% yes) | 80.8 | 67.1 | .185 |
| Current inattention symptoms (mean) | 2.9 | 3.6 | .099 |
| Current hyperactivity-impulsivity symptoms (mean) | 2.5 | 2.9 | .270 |
| Childhood inattention symptoms (mean) | 3.6 | 4.4 | .084 |
| Childhood hyperactivity-impulsivity symptoms (mean) | 3.6 | 3.9 | .369 |
| IQ (mean) | 113.1 | 113.2 | .779 |
| Processing speed factor z-score (mean) | .04 | −.02 | .676 |
| Working memory factor z-score (mean) | −.01 | −.01 | .974 |
| Interference control factor z-score (mean) | .06 | −.02 | .786 |
| Inhibition factor z-score (mean) | .26 | −.03 | .146 |
| Arousal factor z-score (mean) | −.28 | .02 | .092 |
| Response variability factor z-score (mean) | .12 | −.02 | .838 |
| Professional impairment factor (mean) | 17.0 | 18.5 | .396 |
| Daily responsibility impairment factor (mean) | 9.0 | 9.2 | .614 |
| Relational impairment factor (mean) | 13.6 | 12.7 | .600 |
| Perceived Stress Scale score (mean) | 20.0 | 19.3 | .456 |
| Daily Life Hassles Scale score (mean) | 6.1 | 5.1 | .091 |
Note: Normality of scale variables was assessed with the Shapiro-Wilk test of normality. The independent samples t-test was used to compare groups on scale variables that were normally distributed, and the Mann-Whitney test was used to compare groups on scale variables that were non-normally distributed. For dichotomous variables, group differences were tested using a Chi-square Independence test (n => 5 for each group) or a Fisher Exact Test (n < 5 in a group).