Table 1.General characteristics of study subjects by smoking status
|
|
Weighted frequency (%)
|
p-value1
|
|
|
Smoker |
Nonsmoker |
|
Survey year |
2006 |
25 988 (15.9) |
137 751 (84.1) |
0.03 |
2007 |
26 294 (19.3) |
109 833 (80.7) |
|
2008 |
24 395 (21.6) |
88 396 (78.4) |
|
2009 |
24 628 (21.6) |
89 235 (78.4) |
|
School type |
Middle |
26 731 (9.9) |
242 299 (90.1) |
<0.001 |
Academic high |
34 833 (24.0) |
110 018 (76.0) |
|
Vocational high |
39 741 (35.3) |
72 899 (64.7) |
|
Year in school |
Middle 1st |
5479 (6.1) |
84 205 (93.9) |
<0.001 |
Middle 2nd |
8533 (9.4) |
81 896 (90.6) |
|
Middle 3rd |
12 719 (14.3) |
76 199 (85.7) |
|
High 1st |
23 460 (26.1) |
66 526 (73.9) |
|
High 2nd |
26 601 (30.6) |
60 249 (69.4) |
|
High 3rd |
24 513 (30.4) |
56 142 (69.6) |
|
Feeling of happiness |
Happy or fair |
84 437 (18.5) |
372 908 (81.5) |
<0.001 |
Unhappy |
16 867 (24.4) |
52 308 (75.6) |
|
Perceived stress |
A little or none |
51 756 (16.3) |
266 114 (83.7) |
<0.001 |
Much or very much |
49 548 (23.8) |
158 386 (76.2) |
|
Experience with depression |
No |
53 003 (15.7) |
285 451 (84.3) |
<0.001 |
Yes |
48 301 (25.7) |
139 765 (74.3) |
|
Current alcohol drinking |
No |
25 427 (7.0) |
338 124 (93.0) |
<0.001 |
Yes |
75 877 (46.6) |
87 092 (53.4) |
|
Exposure to secondhand smoke |
No |
37 716 (13.4) |
244 117 (86.6) |
<0.001 |
Yes |
63 588 (26.0) |
181 099 (74.0) |
|
Academic performance |
Average or above |
44 291 (13.7) |
278 893 (86.3) |
<0.001 |
Below average |
57 014 (28.0) |
146 323 (72.0) |
|
Economic status of family |
Average or above |
66 037 (17.3) |
315 592 (82.7) |
<0.001 |
Below average |
35 268 (24.3) |
109 624 (75.7) |
|
Table 2.Factors affecting cigarette smoking
|
|
β1
|
p-value |
Odds ratio (95% CI) |
Survey year2
|
|
0.182 |
<0.001 |
1.200 (1.120, 1.285) |
School type |
Middle |
|
|
1.0 (reference) |
Academic high |
0.333 |
0.02 |
1.395 (1.037, 1.877) |
Vocational high |
0.885 |
<0.001 |
2.423 (1.814, 3.236) |
Year in school2
|
|
0.066 |
0.07 |
1.068 (0.995, 1.146) |
Feeling of happiness |
Happy or fair |
|
|
1.0 (reference) |
Unhappy |
-0.046 |
0.58 |
0.955 (0.810, 1.126) |
Perceived stress |
No |
|
|
1.0 (reference) |
Yes |
0.198 |
<0.001 |
1.218 (1.098, 1.352) |
Experience with depression |
No |
|
|
1.0 (reference) |
Yes |
0.261 |
<0.001 |
1.298 (1.158, 1.455) |
Current alcohol drinking |
No |
|
|
1.0 (reference) |
Yes |
2.146 |
<0.001 |
8.552 (7.563, 9.670) |
Exposure to secondhand smoke |
No |
|
|
1.0 (reference) |
Yes |
0.594 |
<0.001 |
1.811 (1.621, 2.024) |
Academic performance |
Average or above |
|
|
1.0 (reference) |
Below average |
0.751 |
<0.001 |
2.119 (1.871, 2.399) |
Economic status of family |
Average or above |
|
|
1.0 (reference) |
Below average |
-0.006 |
0.92 |
0.994 (0.883, 1.119) |
Table 3.Prevalence of and trend in risk factors affecting cigarette smoking
|
2006 |
2007 |
2008 |
2009 |
β1 (p for trend2) |
Perceived stress |
40.0 (37.3, 42.6) |
40.6 (38.6, 42.7) |
40.3 (38.2, 42.4) |
36.9 (34.9, 38.9) |
-0.036 (0.10) |
Experience with depression |
36.7 (35.2, 38.1) |
38.2 (36.1, 40.3) |
35.0 (33.3, 36.8) |
32.1 (30.2, 34.1) |
-0.069 (<0.001) |
Current alcohol drinking |
31.2 (28.0, 34.4) |
32.8 (29.8, 35.9) |
30.7 (27.1, 34.2) |
28.8 (24.6, 33.0) |
-0.040 (0.32) |
Exposure to secondhand smoke |
41.4 (39.1, 43.6) |
50.6 (48.9, 52.4) |
50.6 (48.3, 52.9) |
44.7 (42.4, 47.0) |
0.054 (0.02) |
Academic performance (below average) |
35.3 (33.8, 36.7) |
38.1 (36.4, 39.8) |
41.2 (39.1, 43.2) |
41.5 (39.2, 43.8) |
0.094 (<0.001) |
Table 4.Prevalence of and trend in cigarette smoking by factors that influence adolescent smoking
|
|
2006 |
2007 |
2008 |
2009 |
β1 (p for trend2) |
School type |
Middle |
8.8 (7.5, 10.0) |
10.5 (8.4, 12.5) |
11.1 (9.3, 12.8) |
9.9 (8.0, 11.8) |
0.050 (0.23) |
Academic high |
17.0 (12.3, 21.7) |
23.5 (18.0, 29.0) |
28.9 (22.7, 35.1) |
29.9 (24.2, 35.7) |
0.248 (<0.001) |
Vocational high |
32.6 (29.1, 36.0) |
34.9 (29.2, 40.5) |
37.2 (30.1, 44.4) |
37.5 (28.2, 46.7) |
0.076 (0.25) |
Perceived stress |
No |
13.2 (10.7, 15.7) |
15.5 (12.5, 18.5) |
18.2 (14.7, 21.7) |
19.6 (15.5, 23.7) |
0.156 (<0.001) |
Yes |
20.8 (16.8, 23.4) |
24.9 (21.6, 28.2) |
26.7 (22.9, 30.5) |
25.1 (20.7, 29.4) |
0.106 (0.03) |
Experience with depression |
No |
12.1 (9.9, 14.3) |
15.7 (12.7, 18.6) |
17.9 (14.8, 21.0) |
18.3 (14.6, 22.0) |
0.162 (<0.001) |
Yes |
22.4 (18.8, 26.0) |
25.2 (21.6, 28.8) |
28.5 (23.6, 33.4) |
28.7 (23.6, 33.7) |
0.111 (0.04) |
Current alcohol drinking |
No |
4.8 (3.5, 6.0) |
6.7 (5.3, 8.1) |
8.4 (6.7, 10.1) |
9.1 (7.3, 10.9) |
0.227 (<0.001) |
Yes |
40.5 (37.0, 43.9) |
45.2 (40.9, 49.5) |
51.6 (46.7, 56.4) |
52.6 (45.8, 59.4) |
0.163 (<0.001) |
Exposure to secondhand smoke |
No |
7.7 (5.9, 9.5) |
14.6 (12.2, 17.0) |
16.3 (13.0, 19.5) |
18.2 (14.4, 22.0) |
0.281 (<0.001) |
Yes |
27.5 (24.4, 30.6) |
23.9 (20.1, 27.7) |
26.9 (22.5, 31.2) |
25.9 (21.2, 30.5) |
0.001 (0.80) |
Academic performance |
Average or above |
11.5 (9.2, 13.7) |
14.8 (12.0, 17.5) |
15.4 (12.6, 18.3) |
14.2 (11.0, 17.5) |
0.093 (0.03) |
Below average |
24.0 (20.3, 27.6) |
26.7 (22.9, 30.6) |
30.5 (25.7, 35.3) |
32.1 (27.0, 37.1) |
0.126 (0.007) |
Table 5.Changes in adjusted odds ratios and trends in cigarette smoking after adjustment for factors that influence adolescent smoking
|
2006 |
2007 |
2008 |
2009 |
β1 (p for trend) |
Baseline (adjust for school and grade) |
1.00 |
1.263 (1.019, 1.566) |
1.481 (1.197, 1.833) |
1.449 (1.147, 1.832) |
0.129 (<0.001) |
Baseline + current alcohol drinking |
1.00 |
1.271 (1.044, 1.548) |
1.642 (1.351, 1.995) |
1.706 (1.380, 2.110) |
0.188 (<0.001) |
Baseline + exposure to secondhand smoke |
1.00 |
1.195 (0.968, 1.475) |
1.410 (1.142, 1.740) |
1.455 (1.156, 1.830) |
0.130 (<0.001) |
Baseline + perceived stress |
1.00 |
1.258 (1.009, 1.568) |
1.479 (1.190, 1.839) |
1.470 (1.157, 1.869) |
0.134 (<0.001) |
Baseline + experience with depression |
1.00 |
1.255 (1.014, 1.554) |
1.504 (1.213, 1.865) |
1.496 (1.180, 1.895) |
0.140 (<0.001) |
Baseline + academic performance |
1.00 |
1.242 (0.998, 1.545) |
1.417 (1.142, 1.757) |
1.373 (1.083, 1.740) |
0.110 (0.003) |