Demographic socioeconomic characteristics of the children studied in the three surveys according to urban area of residence
| Surveys | |||||||
| 1974 | 1992 | 1998 | |||||
| Area A | Area B | Area A | Area B | Area A | Area B | ||
| Subjects n | 2259 | 1229 | 1139 | ||||
| Demography | |||||||
| Sex | M | 1154 (51.1) | 635 (51.7) | 561 (49.2) | |||
| F | 1105 (48.9) | 594 (48.3) | 579 (50.8) | ||||
| Age yrs | |||||||
| <9.9 | 1098 (48.6) | 611 (49.7) | 620 (54.4) | ||||
| >10 | 1161 (51.4) | 618 (50.3) | 518 (45.6) | ||||
| Socio economic characteristics | |||||||
| Living in house with >4 rooms | 5.8 | 31.7 | 9.8 | 44.8 | 10.3 | 45.1 | |
| Father's nonmanual activity | 5.6 | 30.0 | 9.2 | 34.8 | 9.6 | 37.7 | |
| Habitually engaging in organized sport | 32.6 | 57.7 | 37.6 | 64.2 | 39.6 | 61.4 | |
| Household smoking (% of families consuming the given no. of cigarettes·day−1) | |||||||
| 0–19 | 76.2 | 77.4 | 65.5 | 67.7 | 65.4 | 72.8 | |
| 20–39 | 17.7 | 16.7 | 26.1 | 24.4 | 26.7 | 20.3 | |
| >39 | 6.1 | 5.9 | 8.4 | 8.0 | 7.9 | 6.9 | |
Data are presented as n (%) or %
Urban area A: intensive housing, high buildings, chemical industries, heavy traffic, scarce green areas (lower standard of living)
Urban area B: lower and widely spaced buildings, no chemical industries, light traffic, wide green areas (higher standard of living)
significant difference between urban areas, (p<0.05, Chi-squared test)