| 2008/9 | 2010 | 2012 | 2014 | 2016 | Relative change 2016 vs 2008/9 | P value for linear trend |
---|---|---|---|---|---|---|---|
% (95% CI) | % (95% CI) | % (95% CI) | % (95% CI) | % (95% CI) | % | Â | |
Prevalence | |||||||
 Boys | 35.9 [35.1–36.8] | 34.6 [33.8–35.5] | 33.1 [32.3–33.9] | 31.0 [30.2–31.8] | 30.7 [29.8–31.6] | −14.5 | < 0.001 |
 Girls | 34.3 [33.4–35.2] | 33.7 [32.9–34.6] | 32.4 [31.6–33.3] | 30.5 [29.7–31.4] | 30.5 [29.6–31.4] | − 11.1 | < 0.001 |
Area of residence | |||||||
North | |||||||
 Boys | 27.6 [26.2–28.9] | 27.1 [26.0–28.1] | 26.7 [25.5–27.9] | 24.9 [23.6–26.3] | 25.1 [23.7–26.6] | − 9.1 | 0.085 |
 Girls | 25.7 [24.4–27.0] | 26.9 [25.9–28.0] | 26.2 [24.9–27.6] | 24.5 [23.2–25.8] | 25.4 [24.0–26.8] | −1.2 | 0.461 |
Center | |||||||
 Boys | 33.7 [31.9–35.4] | 32.5 [31–34.1] | 31.4 [29.6–33.2] | 29.6 [28.1–31.2] | 29.5 [27.7–31.4] | −12.5 | 0.001 |
 Girls | 33.6 [31.7–35.6] | 31.4 [29.8–33.0] | 29.5 [27.8–31.3] | 29.3 [27.7–30.8] | 29.9 [28.0–31.8] | −11.0 | 0.016 |
South | |||||||
 Boys | 44.2 [42.8–45.6] | 42.8 [41.1–44.4] | 42.5 [41.2–43.7] | 41.1 [39.8–42.4] | 39.5 [38.3–40.7] | −10.6 | < 0.001 |
 Girls | 41.9 [40.4–43.4] | 41.3 [39.7–42.8] | 42.4 [41.2–43.7] | 40.5 [39.1–41.9] | 37.8 [36.5–39.1] | −9.8 | 0.002 |
Mother’s educational level | |||||||
Low | |||||||
 Boys | 39.2 [37.8–40.7] | 37.3 [35.9–38.6] | 37.9 [36.6–39.2] | 35.9 [34.4–37.4] | 36.7 [35.2–38.3] | − 6.4 | 0.212 |
 Girls | 38.4 [36.9–40.0] | 36.7 [35.3–38.2] | 36.9 [35.5–38.3] | 35.3 [33.8–36.9] | 36.1 [34.5–37.6] | − 6.0 | 0.286 |
Medium | |||||||
 Boys | 35.6 [34.2–37.0] | 33.7 [32.5–34.9] | 32.6 [31.5–33.7] | 30.6 [29.4–31.8] | 29.9 [28.7–31.2] | − 16.0 | < 0.001 |
 Girls | 33.2 [31.7–34.6] | 33 [31.9–34.2] | 31.3 [30.1–32.5] | 30.4 [29.2–31.6] | 29.7 [28.4–30.9] | − 10.5 | 0.002 |
High | |||||||
 Boys | 30.3 [28.0–32.7] | 30.0 [28.0–32.0] | 25.0 [23.3–26.8] | 24.8 [23.3–26.3 | 25.8 [24.3–27.4] | − 14.9 | 0.002 |
 Girls | 26.5 [24.5–28.6] | 27.9 [26.1–29.8] | 25.6 [23.9–27.4] | 23.1 [21.5–24.7] | 24.6 [22.9–26.4] | − 7.2 | 0.051 |
Mother’s citizenshipa | |||||||
Italian | |||||||
 Boy | – | 34.9 [34.0–35.8] | 33.4 [32.6–34.2] | 30.9 [30.0–31.8] | 30.2 [29.2–31.1] | − 13.5 | < 0.001 |
 Girls | – | 34.3 [33.4–35.2] | 32.6 [31.7–33.4] | 30.9 [30.0–31.8] | 30.5 [29.6–31.5] | − 11.1 | 0.002 |
Foreign | |||||||
 Boys | – | 31.1 [28.8–33.4] | 31.0 [28.9–33.2] | 31.5 [29.4–33.7] | 34.4 [31.8–37.1] | + 10.6 | 0.029 |
 Girls | – | 27.9 [25.8–30.2] | 29.5 [27.1–32.1] | 27.1 [25.1–29.3] | 29.2 [27.0–31.4] | + 4.7 | 0.825 |