Table 1 Characteristics of children under 6 years old who participated in the study
Characteristics | Frequency (n) | Percentage (%) |
|---|---|---|
Sex of children | ||
  Female | 2723 | 49.2 |
  Male | 2806 | 50.8 |
Age of children (months) | ||
  0-11 | 716 | 12.9 |
  12-23 | 800 | 14.5 |
  24-35 | 835 | 15.1 |
  36-47 | 914 | 16.5 |
 48-59 | 1150 | 20.8 |
  60-71 | 1114 | 20.1 |
Birth weight | ||
  <2500 g | 203 | 3.7 |
  2500-3999 g | 4968 | 89.9 |
  ≥4000 g | 358 | 6.5 |
Preterm birth | ||
  No | 5264 | 95.2 |
  Yes | 265 | 4.8 |
Left behind children | ||
  No | 3184 | 57.6 |
  Yes | 2345 | 42.4 |
Only child | ||
  No | 4157 | 75.2 |
  Yes | 1372 | 24.8 |
Passive smoking | ||
  No | 3110 | 56.2 |
  Yes | 2419 | 43.8 |
Regular physical examination | ||
  No | 634 | 11.5 |
  Yes | 4895 | 88.5 |