Table 1 Characteristics of the study population (Poland, 2014–15, n = 250)
| Â | N (%) |
|---|---|
Sex of the child | |
 Female | 134 (54) |
 Male | 116 (46) |
Child age at examinationa | 7.2 ± 0.23 |
BMI groups | |
 Underweight | 15 (6) |
 Recommended weight | 192 (77) |
 Overweight/Obese | 43 (17) |
Place of residence at 7 yr | |
 Urban | 216 (86) |
 Rural | 34 (14) |
Urinary cotinine levels at 7 yr | |
  < 2.1 ng/ml | 148 (59) |
  > 2.1 ng/ml | 101 (41) |
Maternal age at delivery | |
  < 30 years | 155 (62) |
   > 30 years | 95 (38) |
Socioeconomic status of the family at 7 yr | |
 Most affluent (Very good) | 50 (20) |
 Affluent (Good) | 195 (78) |
 Least affluent (Poor or very poor) | 5 (2) |
Maternal educational level at 7 yr (years of completed education) | |
  ≤ 9 | 5 (2) |
 10–12 | 83 (33) |
  > 12 | 162 (65) |
Maternal occupational status at 7 yr | |
 No | 28 (11) |
 Yes | 219 (89) |