TABLE 2.
Outcomes of assessments of attention and working memory and inhibitory control at 27 mo of age by treatment group1
| Outcome | Treatment (n = 77) | Control (n = 73) | Unadjusted | P | Adjusted2 | P |
| Attention | ||||||
| Single-object task | ||||||
| Total duration of time spent looking at the toy (s)3 | 238.8 ± 51.14 | 246.6 ± 41.0 | −7.8 (−22.8, 7.2)5 | 0.31 | −12.0 (−27.7, 3.5) | 0.13 |
| Percentage of time spent looking at the toy (%) | 84.1 ± 11.8 | 86.0 ± 9.3 | −0.02 (−0.1, 0.02) | 0.28 | −0.02 (−0.1, 0.02) | 0.33 |
| Average length of look at the toy (s) | 27.1 ± 19.4 | 27.7 ± 21.9 | −0.5 (−7.2, 6.2) | 0.88 | −2.5 (−9.5, 4.4) | 0.47 |
| No. of looks at the toy | 11.4 ± 4.6 | 11.6 ± 4.6 | −0.2 (−1.7, 1.3) | 0.76 | 0.1 (−1.5, 1.7) | 0.90 |
| No. of times looked away from the toy | 10.0 ± 4.5 | 10.4 ± 4.3 | −0.3 (−1.7, 1.1) | 0.78 | −0.01 (−1.5, 1.5) | 0.99 |
| Multiple-object task | ||||||
| No. of times shifted looks between toys3 | 41.6 ± 11.8 | 42.0 ± 12.4 | −0.5 (−4.4, 3.4) | 0.45 | 2.7 (−4.2, 3.6) | 0.89 |
| Total duration of time looking at toys (s) | 250.6 ± 37.4 | 249.5 ± 30.8 | 1.1 (−9.9, 12.1) | 0.84 | −1.6 (−13.0, 9.9) | 0.79 |
| Percentage of time spent looking at toys (%) | 87.8 ± 9.3 | 87.0 ± 7.2 | 0.01 (−0.02, 0.04) | 0.54 | 0.02 (−0.03, 0.03) | 0.91 |
| No. of times looked away from toys | 14.0 ± 5.8 | 15.7 ± 5.6 | −1.8 (−3.6, 0.02) | 0.05 | −2.0 (−3.9, −0.2) | 0.03 |
| Average length of a look at a toy (s) | 5.3 ± 1.4 | 5.2 ± 1.6 | 0.1 (−0.4, 0.6) | 0.78 | −0.1 (−0.6, 0.4) | 0.81 |
| Distractibility task | ||||||
| Average latency to turn to the distractor when attention was focused (s)367 | 3.5 ± 1.6 | 3.8 ± 1.9 | −0.3 (−0.9, 0.3) | 0.28 | −0.2 (−0.7, 0.4) | 0.58 |
| Percentage of times distracted when focused (%) | 66.2 ± 0.3 | 59.7 ± 0.3 | 0.1 (−0.02, 0.2) | 0.15 | 0.04 (−0.1, 0.1) | 0.34 |
| Average latency to look to the distractor when attention was casual (s)7 | 2.2 ± 1.7 | 2.6 ± 2.1 | −0.4 (−1.0, 0.2) | 0.23 | −0.3 (−0.9, 0.3) | 0.33 |
| Percentage of times distracted when casual (%) | 78.1 ± 0.3 | 74.4 ± 0.3 | 0.04 (−0.6, 0.1) | 0.43 | 0.04 (−0.1, 0.1) | 0.44 |
| Total duration of time spent looking at the distractor when the distractor was on (s) | 89.7 ± 49.7 | 79.9 ± 50.1 | 9.8 (−6.1, 25.7) | 0.23 | 3.9 (−11.7, 19.5) | 0.62 |
| Total duration of time spent looking at the distractor when the distractor was off (s) | 26.8 ± 23.4 | 24.6 ± 21.6 | 2.5 (−4.7, 9.7) | 0.49 | 0.8 (−6.3, 7.9) | 0.82 |
| Working memory and inhibitory control | ||||||
| Average accuracy of locating figurine during test trials (mm)6 | 132.6 ± 55.5 | 120.0 ± 63.4 | 12.6 (−6.4, 31.6) | 0.19 | 8.9 (−10.6, 28.3) | 0.37 |
| Average accuracy of locating figurine during training trials (mm) | 95.6 ± 47.4 | 83.7 ± 39.9 | 11.9 (−2.2, 25.9) | 0.10 | 14.4 (−0.2, 29.1) | 0.05 |
1
Groups were compared by using independent samples t tests and ANCOVA.
2
Adjusted for maternal smoking at baseline (∼18 wk of gestation), child sex, and father's secondary education.
3
Main outcome for the attention task.
4
Mean ± SD (all such values).
5
Mean difference; 95% CI in parentheses (all such values).
6
Primary outcome.
7
Maximum latency: 7 s.