Main characteristics of both study samples
| Characteristic | Population study* | Extreme exposure study† |
|---|---|---|
| *Representative sample; †sampling on exposure extremes (<50 dB,A,Ldn; >60 dB,A,Ldn). | ||
| Sample size (n) | 1280 | 123 |
| Age child (y, mean (SD)) | 9.44 (0.70) | 8.96 (0.45) |
| Age mother(y, mean (SD)) | 36.33 (4.90) | 36.48 (4.68) |
| Sex (% male) | 51 | 55 |
| Body mass index (kg/m2, mean (SD)) | 17.28 (2.61) | 17.49 (2.79) |
| Birth order (%) | ||
| First born | 47 | 44 |
| Second born | 33 | 37 |
| Maternal education (%) | ||
| Basic | 27 | 23 |
| Vocational | 33 | 34 |
| Technical/trade | 24 | 25 |
| High school | 8 | 8 |
| Graduate school | 8 | 14 |
| Single parent (%) | 6 | 7 |
| Housing type (%) | ||
| Multiple dwelling | 22 | 26 |
| Row house | 18 | 21 |
| Single family detached | 60 | 53 |
| Mother current smoking (%) | 29 | 28 |
| Density (people/room, mean (SD)) | 0.85 (0.28) | 1.04 (0.34) |
| Duration of residence (y, mean (SD)) | 10.23 (7.63) | 9.96 (6.33) |
| Breastfeeding (months, mean (SD)) | 3.66 (4.74) | 3.72 (5.35) |
| Noise exposure (dB,A,Ldn, mean (SD)) | 51.67 (7.69) | 53.04 (10.47) |
| Mental health (self report, mean (SD)) | 93.06 (13.65) | 92.84 (12.97) |
| School behaviour (teacher, mean (SD)) | 19.60 (2.54) | 20.04 (2.26) |