Table 1.
Description of characteristics of all BREATHE participants (n = 2,897) and those included in this current study (n = 2,111), Barcelona, 2012 [n (%)].
| Variable | BREATHE participants | Study participants |
|---|---|---|
| Child sex | ||
| Female | 1,441 (49.7) | 1,040 (49.3) |
| Male | 1,456 (50.3) | 1,071 (50.7) |
| Child school level (grade) | ||
| Second | 1,083 (37.4) | 808 (38.2) |
| Third | 1,036 (35.8) | 750 (35.5) |
| Fourth | 778 (26.9) | 553 (26.2) |
| Maternal educational achievement | ||
| None or primary education | 347 (12.0) | 217 (10.3) |
| Secondary education | 781 (27.0) | 618 (29.3) |
| University education | 1,596 (55.1) | 1,260 (59.7) |
| Missing | 173 (5.9) | 16 (0.8) |
| Paternal educational achievement | ||
| None or primary education | 419 (14.5) | 262 (12.4) |
| Secondary education | 848 (29.3) | 652 (30.9) |
| University | 1,418 (49.0) | 1,154 (54.7) |
| Missing | 212 (7.3) | 43 (2.0) |
| Maternal employment status | ||
| Unemployed | 476 (16.4) | 358 (17.0) |
| Employee | 1,781 (61.5) | 1,373 (65.0) |
| Self-employed | 453 (15.7) | 352 (16.7) |
| Missing | 187 (6.5) | 28 (1.3) |
| Paternal employment status | ||
| Unemployed | 260 (9.0) | 212 (10.0) |
| Employee | 1,565 (54.0) | 1,200 (56.9) |
| Self-employed | 834 (28.8) | 637 (30.2) |
| Missing | 238 (8.2) | 62 (2.9) |
| Adopted child | ||
| Yes | 105 (3.6) | 84 (4.0) |
| No | 2,616 (90.3) | 2,007 (95.1) |
| Missing | 176 (6.1) | 20 (1.0) |
| Parental marital status | ||
| Non-single parent | 2,312 (79.8) | 1,770 (83.9) |
| Single parent | 411 (14.2) | 325 (15.4) |
| Missing | 174 (6.0) | 16 (0.8) |
| Exposure to environmental tobacco smoke | ||
| Yes | 337 (11.6) | 275 (13.0) |
| No | 2,382 (82.2) | 1,814 (85.9) |
| Missing | 178 (6.1) | 22 (1.0) |
| Maternal smoking during pregnancy | ||
| Yes | 261 (9.0) | 210 (10.0) |
| No | 2,395 (82.7) | 1,831 (86.7) |
| Missing | 241 (8.3) | 70 (3.3) |
| Preterm birth | ||
| Yes | 200 (6.9) | 159 (7.5) |
| No | 2,434 (84.0) | 1,867 (88.0) |
| Missing | 263 (9.1) | 86 (4.1) |
| Breastfeeding | ||
| No | 476 (16.4) | 394 (18.7) |
| < 6 months | 1,422 (49.1) | 1,074 (50.9) |
| > 6 months | 788 (27.2) | 597 (28.3) |
| Missing | 211 (7.3) | 46 (2.2) |
| Ethnicity | ||
| Spanish | 2,574 (88.9) | 1,908 (90.4) |
| Non-Spanish | 279 (9.6) | 189 (9.0) |
| Missing | 44 (1.5) | 14 (0.7) |