Distribution of 2.5 year old children in Quebec longitudinal study of child development (QLSCD 1998–2002) according to their characteristics, their neonatal health problems, and their environment during the past 12 months (n = 1946)
| % | 95% CI | |
|---|---|---|
| *Small for gestational age (<10th centile) according to the Kramer curve 2001. †Coefficient of variation between 15% and 25%; data should be interpreted with caution. The coefficient of variation is a measure of dispersion of the data around the mean. It is the ratio of the standard deviation to the mean of a distribution. It does not have any metric and is usually expressed in percentage. Large coefficients of variation indicate a large dispersion of data around the mean and a loss of accuracy of the mean estimate (BMDP statistical software, Los Angeles, 1990). | ||
| Baby’s sex | ||
| Female | 49.4 | 47.1 to 51.8 |
| Male | 50.6 | 48.2 to 52.9 |
| Birth rank | ||
| 1st | 44.3 | 41.9 to 46.6 |
| 2nd | 39.1 | 36.9 to 41.4 |
| 3rd or more | 16.6 | 14.9 to 18.3 |
| Congenital abnormality | ||
| No | 92.0 | 90.7 to 93.3 |
| Yes | 8.0 | 6.7 to 9.3 |
| Small for gestational age <10th centile* | ||
| No | 93.5 | 92.3 to 94.7 |
| Yes | 6.5 | 5.3 to 7.7 |
| Premature birth (<37 weeks) | ||
| No | 93.5 | 92.1 to 94.8 |
| Yes | 6.5 | 5.2 to 7.9 |
| Parents’ smoking (past 12 months) | ||
| No parent smoking | 65.7 | 63.4 to 68.0 |
| One parent who smokes in the home | 21.3 | 19.2 to 23.3 |
| Two parents who smoke in the home | 13.0 | 11.5 to 14.7 |
| Length of exclusive breast feeding | ||
| Never breast fed | 28.2 | 26.1 to 30.3 |
| Breast fed since birth, but not exclusively | 5.8 | 4.6 to 6.9 |
| 1 day to 4 weeks | 18.9 | 17.0 to 20.8 |
| 5–9 weeks | 20.1 | 18.2 to 21.9 |
| 10–14 weeks | 10.5 | 9.2 to 11.9 |
| 15 weeks or longer | 16.6 | 14.9 to 18.3 |
| Type of child care (past 12 months) | ||
| At home with the mother or another person | 49.6 | 47.2 to 51.9 |
| Outside of the home | 32.4 | 30.2 to 34.5 |
| At a day care centre | 16.8 | 15.1 to 18.5 |
| Variable child care | 1.2† | 0.8 to 1.8 |