Time period
|
2000–2001
|
2002–2003
|
2004–2005
|
2006–2007
|
2008–2009
|
2010–2011
|
2000–2011
|
---|
|
OR (95% CI)
|
OR (95% CI)
|
OR (95% CI)
|
OR (95% CI)
|
OR (95% CI)
|
OR (95% CI)
|
OR (95% CI)
|
---|
Boys
| | | | | | | |
Model 1
| | | | | | | |
Mild
|
1.00
|
0.90 (0.86-0.95)
|
0.99 (0.94-1.03)
|
1.05 (1.01-1.10)
|
1.05 (1.01-1.10)
|
0.92 (0.88-0.96)
|
1.00 (1.00-1.01)
|
Moderate
|
1.00
|
0.88 (0.84-0.93)
|
0.96 (0.91-1.01)
|
1.02 (0.97-1.07)
|
1.03 (0.98-1.08)
|
0.87 (0.83-0.92)
|
1.00 (0.99-1.01)
|
Severe
|
1.00
|
0.95 (0.87-1.04)
|
1.00 (0.92-1.09)
|
1.07 (0.98-1.16)
|
1.08 (0.99-1.18)
|
1.04 (0.96-1.14)
|
1.02 (1.01-1.03)
|
Model 2
| | | | | | | |
Mild
|
1.00
|
0.91 (0.87-0.96)
|
1.00 (0.95-1.04)
|
1.06 (1.02-1.11)
|
1.06 (1.02-1.11)
|
0.93 (0.88-0.97)
|
1.01 (1.00-1.01)
|
Moderate
|
1.00
|
0.89 (0.85-0.94)
|
0.98 (0.93-1.03)
|
1.04 (0.99-1.09)
|
1.05 (1.00-1.10)
|
0.89 (0.84-0.94)
|
1.00 (0.99-1.01)
|
Severe
|
1.00
|
0.97 (0.89-1.06)
|
1.04 (0.95-1.13)
|
1.10 (1.01-1.20)
|
1.11 (1.02-1.21)
|
1.08 (0.99-1.18)
|
1.03 (1.01-1.04)
|
N
|
47586
|
50774
|
53057
|
54315
|
54132
|
51116
|
310980
|
Girls
| | | | | | | |
Model 1
| | | | | | | |
Mild
|
1.00
|
0.89 (0.86-0.92)
|
0.93 (0.89-0.96)
|
0.94 (0.91-0.98)
|
0.96 (0.92-0.99)
|
0.93 (0.89-0.96)
|
1.00 (0.99-1.00)
|
Moderate
|
1.00
|
0.86 (0.83-0.90)
|
0.95 (0.91-0.98)
|
0.98 (0.95-1.02)
|
0.98 (0.95-1.02)
|
0.98 (0.95-1.02)
|
1.01 (1.00-1.02)
|
Severe
|
1.00
|
0.84 (0.79-0.90)
|
1.04 (0.97-1.10)
|
1.02 (0.96-1.08)
|
1.08 (1.01-1.15)
|
1.16 (1.09-1.24)
|
1.04 (1.03-1.06)
|
Model 2
| | | | | | | |
Mild
|
1.00
|
0.90 (0.86-0.93)
|
0.94 (0.90-0.97)
|
0.95 (0.92-0.99)
|
0.97 (0.93-1.003)
|
0.94 (0.90-0.97)
|
1.00 (0.99-1.00)
|
Moderate
|
1.00
|
0.88 (0.84-0.91)
|
0.97 (0.93-1.01)
|
1.01 (0.97-1.05)
|
1.007 (0.97-1.05)
|
1.009 (0.97-1.05)
|
1.02 (1.01-1.02)
|
Severe
|
1.00
|
0.86 (0.81-0.92)
|
1.07 (1.01-1.14)
|
1.06 (0.99-1.12)
|
1.12 (1.05-1.19)
|
1.21 (1.14-1.29)
|
1.05 (1.04-1.06)
|
N
|
47049
|
49236
|
51713
|
54005
|
54035
|
51066
|
307104
|
- Model 1: time period as factor, no covariates.
- Model 2: time period as factor; grade, family structure, unemployment and parents’ education as covariates.
- Statistically significant (p < 0.05) are in bold.