Characteristic | n (%) | Ever smokers (%) | Crude OR | P value | Adjusted OR* | P value |
(95% CI) | (95% CI) | |||||
Age | <0.001 | 0.510 | ||||
10 | 217 (0.6) | 9 (4.1) | 1 | 1 | ||
11 | 5760 (14.7) | 161 (2.8) | 0.7 (0.3 to 1.3) | 1.9 (0.6 to 6.1) | ||
12 | 12 932 (32.9) | 328 (2.5) | 0.6 (0.3 to 1.2) | 1.7 (0.5 to 5.4) | ||
13 | 13 247 (33.7) | 277 (2.1) | 0.5 (0.3 to 1.0) | 1.7 (0.5 to 5.4) | ||
14 | 6671 (17.0) | 117 (1.8) | 0.4 (0.2 to 0.8) | 1.4 (0.5 to 4.6) | ||
15 | 455 (1.2) | 22 (4.8) | 1.2 (0.5 to 2.6) | 2.0 (0.5 to 7.2) | ||
Gender | <0.001 | 0.003 | ||||
Male | 20 020 (51.0) | 597 (3.0) | 1.8 (1.6 to 2.1) | 1.3 (1.1 to 1.6) | ||
Female | 19 262 (49.0) | 317 (1.6) | 1 | 1 | ||
School locality | 0.773 | – | ||||
Urban | 7803 (19.9) | 185 (2.4) | 1.02 (0.9 to 1.2) | |||
Rural | 31 479 (80.1) | 729 (2.3) | 1 | |||
School type | <0.001 | 0.108 | ||||
Government | 16 786 (42.7) | 416 (2.5) | 1.4 (1.2 to 1.6) | 1.2 (1.0 to 1.6) | ||
Aided | 7584 (19.3) | 227 (3.0) | 1.7 (1.4 to 2.0) | 1.3 (1.0 to 1.6) | ||
Private | 14 912 (38.0) | 271 (1.8) | 1 | 1 | ||
Religion | <0.001 | 0.068 | ||||
Hindu | 32 713 (83.3) | 710 (2.2) | 1 | 1 | ||
Christian | 2016 (5.1) | 51 (2.5) | 1.2 (0.9 to 1.6) | 1.1 (0.8 to 1.6) | ||
Jain | 152 (0.4) | 7 (4.6) | 2.2 (1.0 to 4.7) | 1.7 (0.6 to 5.2) | ||
Muslim | 4272 (10.9) | 138 (3.2) | 1.5 (1.3 to 1.8) | 1.4 (1.1 to 1.8) | ||
Other | 129 (0.3) | 8 (6.2) | 3.0 (1.5 to 6.1) | 1.6 (0.6 to 4.2) | ||
Home smoking tobacco use allowed | <0.001 | <0.001 | ||||
No | 35 400 (90.1) | 588 (1.7) | 1 | 1 | ||
Yes | 3882 (9.9) | 326 (8.4) | 5.4 (4.7 to 6.2) | 2.8 (2.3 to 3.4) | ||
Family smoking tobacco use | ||||||
Father: Yes | 4226 (10.8) | 258 (6.1) | 3.4 (2.9 to 3.9) | <0.001 | 1.9 (1.5 to 2.3) | <0.001 |
No | 35 056 (89.2) | 656 (1.9) | 1 | 1 | ||
Mother: Yes | 386 (1.0) | 99 (25.7) | 16.1 (12.7 to 20.5) | <0.001 | 5.0 (3.4 to 7.2) | <0.001 |
No | 38 896 (99.0) | 815 (2.1) | 1 | 1 | ||
Siblings: Yes | 721 (1.8) | 127 (17.6) | 10.3 (8.4 to 12.6) | <0.001 | 3.1 (2.2 to 4.2) | <0.001 |
No | 38 561 (98.2) | 787 (2.0) | 1 | 1 | ||
Others: Yes | 6119 (15.6) | 160 (2.6) | 1.2 (1.0 to 1.4) | 0.104 | – | |
No | 33 163 (84.4) | 754 (2.3) | 1 | |||
Friends smoking tobacco use | <0.001 | <0.001 | ||||
None | 34 430 (87.6) | 352 (1.0) | 1 | 1 | ||
One | 763 (1.9) | 132 (17.3) | 20.3 (16.3 to 25.1) | 10.8 (8.1 to 14.4) | ||
Two | 492 (1.3) | 137 (27.9) | 37.4 (29.9 to 46.7) | 16.5 (12.2 to 22.4) | ||
Three | 579 (1.5) | 121 (20.9) | 25.6 (20.4 to 32.0) | 11.9 (8.7 to 16.2) | ||
Not sure | 3018 (7.7) | 172 (5.7) | 5.9 (4.9 to 7.0) | 4.0 (3.1 to 5.0) | ||
Smoking seen in school | <0.001 | 0.926 | ||||
No | 28 218 (71.8) | 545 (1.9) | 1 | 1 | ||
Yes | 11 064 (28.2) | 369 (3.3) | 1.8 (1.5 to 2.0) | 1.0 (0.8 to 1.2) | ||
Mother’s education | <0.001 | 0.425 | ||||
Illiterate | 2457 (6.4) | 94 (3.8) | 4.3 (2.5 to 7.7) | 1.1 (0.6 to 2.4) | ||
Primary | 16 255 (42.0) | 407 (2.5) | 2.8 (1.6 to 4.8) | 0.9 (0.5 to 1.8) | ||
High school | 14 466 (37.4) | 325 (2.2) | 2.5 (1.5 to 4.3) | 1.1 (0.6 to 2.1) | ||
Graduate | 3964 (10.2) | 53 (1.3) | 1.4 (0.8 to 2.7) | 1.0 (0.5 to 2.0) | ||
Postgraduate | 1554 (4.0) | 14 (0.9) | 1 | 1 | ||
Father’s education | <0.001 | 0.013 | ||||
Illiterate | 1757 (4.6) | 79 (4.5) | 7.0 (12.5 to 3.9) | 2.8 (1.4 to 5.4) | ||
Primary | 16 018 (41.5) | 410 (2.6) | 3.9 (6.7 to 2.3) | 2.6 (1.4 to 4.9) | ||
High school | 14 535 (37.7) | 326 (2.2) | 3.4 (5.9 to 2.0) | 2.9 (1.6 to 5.4) | ||
Graduate | 4129 (10.7) | 67 (1.6) | 2.5 (4.4 to 1.4) | 2.5 (1.3 to 4.8) | ||
Postgraduate | 2106 (5.5) | 14 (0.7) | 1 | 1 | ||
Wealth quintile | <0.001 | <0.001 | ||||
Lower | 7735 (19.7) | 331 (4.3) | 2.8 (2.3 to 3.4) | 2.7 (2.1 to 3.6) | ||
Lower middle | 7315 (18.6) | 180 (2.5) | 1.6 (1.3 to 2.0) | 1.5 (1.1 to 2.0) | ||
Middle | 8464 (21.6) | 171 (2.0) | 1.3 (1.0 to 1.6) | 1.4 (1.0 to 1.9) | ||
Upper middle | 7855 (20.0) | 106 (1.3) | 0.9 (0.7 to 1.1) | 1.0 (0.7 to 1.4) | ||
Upper | 7867 (20.1) | 124 (1.6) | 1 | 1 | ||
Rebelliousness | <0.001 | <0.001 | ||||
No | 24 500 (62.4) | 311 (1.3) | 1 | 1 | ||
Mild | 10 917 (27.8) | 260 (2.4) | 1.9 (1.6 to 2.2) | 1.7 (1.4 to 2.1) | ||
Moderate | 3396 (8.6) | 267 (7.9) | 6.6 (5.7 to 7.9) | 3.8 (3.0 to 4.8) | ||
Severe | 469 (1.2) | 76 (16.2) | 15.0 (11.5 to 19.7) | 6.4 (4.4 to 9.5) | ||
High self-esteem | <0.001 | 0.001 | ||||
Strongly agree | 18 169 (46.3) | 280 (1.54) | 1 | 1 | ||
Agree | 8799 (22.4) | 240 (2.7) | 1.8 (1.5 to 2.1) | 1.3 (1.0 to 1.6) | ||
Neither agree or disagree | 6817 (17.4) | 191 (2.8) | 1.8 (1.5 to 2.2) | 1.2 (1.0 to 1.6) | ||
Disagree | 3099 (7.9) | 123 (4.0) | 2.6 (1.7 to 3.3) | 1.8 (1.4 to 2.4) | ||
Strongly disagree | 2398 (6.1) | 80 (3.34) | 2.2 (2.1 to 2.8) | 1.4 (1.0 to 2.0) | ||
School performance | <0.001 | 0.001 | ||||
Excellent | 15 046 (38.3) | 253 (1.7) | 1 | 1 | ||
Good | 17 993 (45.8) | 342 (1.9) | 1.1 (0.9 to 1.3) | 1.1 (0.9 to 1.3) | ||
Average | 5337 (13.6) | 249 (4.7) | 2.9 (2.4 to 3.4) | 1.4 (1.1 to 1.9) | ||
Below average | 906 (2.3) | 70 (7.7) | 4.9 (3.7 to 6.4) | 1.9 (1.3 to 2.8) |
*All p<0.05 after adjustment for gender, father’s education, family members smoking, friends smoking, wealth quintile, rebelliousness, self-esteem and school performance.
NS, not significant in mutually adjusted model.