| n | 10 798 | 4273 | 7845 | 3415 |
| Gender: | | | | |
| Female | 5296 (38.0%) | 2292 (15.9%) | 3969 (28.5%) | 2027 (14.5%) |
| Male | 5451 (41.7%) | 1954 (14.3%) | 3816 (29.2%) | 1348 (10.3%) |
| Missing | 51 (21.4%) | 27 (9.2%) | 60 (25.2%) | 40 (16.8%) |
| Age: | | | | |
| 14 years | 7137 (40.9%) | 2877 (15.9%) | 4875 (27.9%) | 2041 (11.7%) |
| 15 years | 6636 (37.6%) | 1380 (13.6%) | 2944 (30.5%) | 1357 (14.0%) |
| Ethnicity: | | | | |
| New Zealand European | 7123 (42.4%) | 3026 (17.5%) | 4697 (27.9%) | 1564 (9.3%) |
| Māori | 1116 (21.5%) | 498 (9.2%) | 2000 (38.6%) | 1332 (25.7%) |
| Pasifika | 697 (34.1%) | 247 (10.8%) | 662 (32.4%) | 317 (15.5%) |
| Asian | 1619 (60.8%) | 429 (15.2%) | 352 (13.2%) | 151 (5.7%) |
| Other | 183 (47.7%) | 56 (14.3%) | 96 (25.0%) | 26 (6.8%) |
| Missing | 60 (36.6%) | 17 (9.1%) | 38 (23.2%) | 25 (15.2%) |
| Smoking in the home: | | | | |
| No | 9446 (45.2%) | 3433 (16.1%) | 5551 (26.6%) | 1862 (8.9%) |
| Sometimes | 637 (19.5%) | 372 (11.0%) | 1229 (37.6%) | 900 (27.5%) |
| Yes | 686 (24.8%) | 392 (13.9%) | 961 (34.8%) | 614 (22.2%) |
| Missing | 29 (8.9%) | 76 (3.7%) | 104 (32.0%) | 39 (12.0%) |
| Parental smoking: | | | | |
| None | 7916 (48.7%) | 2890 (17.4%) | 3865 (23.8%) | 1132 (7.0%) |
| One | 2054 (31.0%) | 889 (13.0%) | 2381 (35.9%) | 1084 (16.3%) |
| Two | 735 (19.2%) | 375 (9.6%) | 1441 (37.7%) | 1129 (29.5%) |
| Missing | 93 (17.4%) | 119 (9.2%) | 158 (29.5%) | 70 (13.1%) |
| Peer smoking: | | | | |
| None | 9022 (55.9%) | 2785(16.9%) | 3439 (21.3%) | 389 (2.4%) |
| One | 1496 (21.2%) | 1174(16.3%) | 3133 (44.4%) | 1032 (14.6%) |
| Two or more | 187 (5.3%) | 195 (5.4%) | 1115 (31.6%) | 1924 (54.6%) |
| Missing | 93 (17.4%) | 119 (9.2%) | 158 (29.5%) | 70 (13.1%) |
| School socioeconomic status: | | | | |
| Low | 1292 (32.1%) | 411 (9.7%) | 1304 (32.3%) | 834 (20.7%) |
| Medium | 4689 (38.9%) | 1726 (13.7%) | 3624 (30.1%) | 1594 (13.2%) |
| High | 4817 (43.1%) | 2136 (18.5%) | 2917 (26.1%) | 987 (8.8%) |