| 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 | 12.9 [12.3–13.5] | 11.8 [11.2–12.3] | 10.9 [10.5–11.4] | 10.3 [9.76–10.8] | 9.7 [9.2–10.2] | −24.7 | 0.001 |
 Girls | 10.9 [10.4–11.5] | 10.5 [9.9–11.1] | 10.2 [9.7–10.8] | 9.4 [8.9–9.9] | 8.8 [8.3–9.3] | − 19.2 | 0.034 |
Area of residence | |||||||
North | |||||||
 Boys | 7.6 [6.9–8.3] | 7.9 [7.3–8.5] | 7.0 [6.3–7.6] | 7.1 [6.4–7.9] | 6.0 [5.3–6.7] | − 21.4 | 0.042 |
 Girls | 6.5 [5.7–7.4] | 6.8 [6.2–7.3] | 6.3 [5.6–7.0] | 6.2 [5.6–6.8] | 5.9 [5.2–6.7] | − 9.5 | 0.672 |
Center | |||||||
 Boys | 10.8 [9.6–12.1] | 9.6 [8.6–10.7] | 8.8 [7.9–9. 9] | 8.9 [8.0–9.9] | 9.1 [8.1–10.3] | − 15.6 | 0.235 |
 Girls | 8.9 [7.8–10.2] | 8.6 [7.6–9.7] | 8.7 [7.5–9.9] | 8.0 [7.0–9.1] | 7.0 [6.2–8.0] | − 21.5 | 0.028 |
South | |||||||
 Boys | 18.5 [17.4–19.6] | 16.7 [15.5–17.8] | 17.4 [16.5–18.3] | 16.0 [15.0–17.0] | 15.5 [14.6–16.5] | − 16.2 | 0.017 |
 Girls | 15.7 [14.7–16.8] | 15.0 [13.8–16.2] | 16.4 [15.4–17.4] | 15.1 [14.0–16.1] | 13.8 [13.0–14.7] | − 12.1 | 0.172 |
Mother’s educational level | |||||||
Low | |||||||
 Boys | 16.7 [15.7–17.9] | 14.6 [13.6–15.6] | 14.6 [13.7–15.5] | 14.9 [13.8–16] | 13.8 [12.6–14.9] | − 17.4 | 0.141 |
 Girls | 14.4 [13.3–15.5] | 13.3 [12.3–14.4] | 14.1 [13.2–15.1] | 13.4 [12.3–14.5] | 12.6 [11.6–13.7] | − 12.5 | 0.443 |
Medium | |||||||
 Boys | 11.2 [10.3–12.0] | 10.6 [9.8–11.5] | 10.0 [9.3–10.7] | 9.2 [8.4–9.9] | 9.1 [8.4–9.8] | − 19.0 | 0.005 |
 Girls | 9.8 [8.9–10.7] | 9.5 [8.8–10.4] | 9.0 [8.3–9.8] | 8.3 [7.7–9.0] | 8.2 [7.5–8.9] | − 16.3 | 0.014 |
High | |||||||
 Boys | 8.1 [6.8–9.7] | 6.7 [5.7–7.8] | 5.6 [4.8–6.4] | 5.4 [4.7–6.1] | 6.2 [5.4–7.0] | − 24.4 | 0.096 |
 Girls | 5.0 [4.0–6.2] | 5.8 [4.8–6.9] | 5.4 [4.5–6.3] | 5.1 [4.3–6.0] | 4.8 [4.1–5.6] | − 3.6 | 0.912 |
Mother’s citizenshipa | |||||||
Italian | |||||||
 Boys | – | 11.6 [11.0–12.2] | 11.1 [10.5–11.6] | 10.1 [9.5–10.6] | 9.4 [8.9–10.0] | −18.7 | 0.061 |
 Girls | – | 10.8 [10.2–11.4] | 10.3 [9.7–10.8] | 9.4 [8.9–10.0] | 8.9 [8.4–9.4] | −17.8 | 0.05 |
Foreign | |||||||
 Boys | – | 10.5 [9.0–12.1] | 9.3 [8.0–10.7] | 10.7 [9.2–12.4] | 10.5 [9.1–12.2] | 0.0 | 0.354 |
 Girls |  | 7.4 [6.1–8.8] | 8.5 [7.1–10.2] | 7.7 [6.6–9.1] | 7.8 [6.5–9.2] | 5.3 | 0.881 |