Table 1.
Characteristics | Birth | 4–5-y follow-up | p-Valuec | p-Valuea | 7-y follow-up | p-Valuec | p-Valued | p-Valuee | ||
---|---|---|---|---|---|---|---|---|---|---|
Includea () | Excludedb () | Includea () | Excludedb () | |||||||
Sex (Female) | 48.0% | 48.8% | 46.1% | 0.39 | 0.73 | 48.8% | 40.9% | 0.21 | 0.72 | 0.99 |
Preterm birth (yes) | 4.4% | 3.7% | 3.9% | 0.89 | 0.42 | 3.4% | 7.7% | 0.08 | 0.21 | 0.70 |
Maternal educational attainment | 0.04 | 0.01 | 0.21 | 0.81 | ||||||
No or primary school | 31.0% | 26.1% | 29.9% | 24.7% | 30.8% | |||||
Secondary school | 43.0% | 42.7% | 46.4% | 43.6% | 47.7% | |||||
University | 26.1% | 31.2% | 23.7% | 31.7% | 21.5% | |||||
Maternal IQf | 10.5 (3.7) | 10.5 (4.4) | 10.5 (4.4) | 0.53 | 0.84 | 10.5 (4.4) | 10.5 (4.7) | 0.66 | 0.30 | 0.40 |
Maternal smoking during pregnancy (yes) | 35.6% | 33.6% | 33.1% | 0.88 | 0.32 | 31.7% | 33.3% | 0.78 | 0.04 | 0.38 |
Exposure to environmental tobacco smoke at 4-year follow-up (yes) | *** | 50.2% | 47.7% | 0.44 | *** | 51.2% | 48.4% | 0.67 | *** | 0.69 |
Exposure to environmental tobacco smoke at 7-year follow-up (yes) | *** | *** | *** | *** | *** | 30.3% | 15.2% | 0.01 | *** | *** |
Neighborhood socioeconomic statusg | 0.6 (0.2) | 0.6 (0.2) | 0.7 (0.3) | 0.33 | 0.22 | 0.6 (0.2) | 0.6 (0.2) | 0.12 | 0.09 | 0.65 |
Note: p-Values are reported for chi-squared test for categorical variables and Mann–Whitney U test for continuous variables. For continuous variables, median (IQR) and for categorical variables count (percentage) of each category has been reported.
p-Value for the difference between children with available data at birth and those included at the 4-year follow-up.
Children participated in the 4-y follow-up but did not have data on K-CPT.
p-Value for the difference between children included and excluded in each follow-up.
p-Value for the difference between children with available data at birth and those included at the 7-year follow-up.
p-Value for the difference between children with available data at the 4-year follow-up and those included at 7-y follow-up.
Wechsler Adult Intelligence Scale (WAIS-IV), Similarities subscale.
Urban vulnerability index.