Table 1 Unadjusted and adjusted odds of smoking being allowed in the family car (excluding children whose family does not have a car)
From: Smoking in cars in England: a study of school students in an English city
Variable | Number of students (% where smoking allowed) | Univariable model | Multivariable model* | ||||
|---|---|---|---|---|---|---|---|
Odds ratio | Confidence interval | P-value | Odds ratio | Confidence interval | P-value | ||
Sex | |||||||
Boy | 1,964 (12.1) | 1.00 | 0.287 | ||||
Girl | 2,003 (13.7) | 1.15 | 1.02-1.31 | ||||
Missing | 18 (16.7) | 1.45 | 0.34-6.16 | ||||
School year | |||||||
Year 7 | 589 (12.2) | 1.00 | 0.063 | ||||
Year 8 | 1,021 (13.9) | 1.16 | 0.91-1.48 | ||||
Year 9 | 984 (10.8) | 0.87 | 0.61-1.24 | ||||
Year 10 | 972 (13.8) | 1.15 | 0.81-1.63 | ||||
Year 11 | 408 (14.2) | 1.19 | 0.82-1.73 | ||||
Missing | 11 (36.4) | 4.10 | 0.84-20.0 | ||||
Deprivation | |||||||
V (least deprived) | 1,026 (4.9) | 1.00 | <0.001 | 1.00 | <0.001 | ||
IV | 437 (10.8) | 2.35 | 1.72-3.21 | 1.85 | 1.11-3.06 | ||
III | 534 (12.2) | 2.70 | 1.72-4.26 | 1.52 | 0.95-2.43 | ||
II | 467 (15.2) | 3.50 | 2.56-4.79 | 2.29 | 1.43-3.66 | ||
I (most deprived) | 444 (22.1) | 5.53 | 2.58-11.86 | 2.51 | 1.60-3.94 | ||
Missing | 1,077 (17.2) | 4.05 | 2.61-6.27 | 2.17 | 1.45-3.23 | ||
Parental smoking | |||||||
Neither parent smokes | 2,771 (3.1) | 1.00 | <0.001 | 1.00 | <0.001 | ||
One parent smokes | 841 (30.0) | 13.20 | 9.07-19.20 | 6.08 | 4.56-8.11 | ||
Both parents smoke | 346 (50.6) | 31.57 | 21.77-45.78 | 9.83 | 6.95-13.90 | ||
Missing | 27 (7.4) | 2.47 | 0.82-7.43 | 1.75 | 0.37-8.34 | ||
Sibling smoking | |||||||
None smokes | 3,511 (10.6) | 1.00 | <0.001 | ||||
At least one smokes | 447 (32.0) | 3.98 | 3.12-5.08 | ||||
Missing | 27 (7.4) | 0.68 | 0.19-2.35 | ||||
Smoking in the main home | |||||||
Not allowed | 3,376 (5.0) | 1.00 | <0.001 | 1.00 | <0.001 | ||
Allowed | 583 (58.3) | 26.39 | 20.04-34.74 | 11.03 | 8.59-14.18 | ||
Missing | 26 (23.1) | 5.66 | 3.03-10.57 | 3.48 | 1.26-9.62 | ||
Friend smoking | |||||||
None | 1,350 (6.4) | 1.00 | <0.001 | 1.00 | <0.001 | ||
One or two | 558 (13.3) | 2.25 | 1.76-2.86 | 1.51 | 1.00-2.28 | ||
Three or more | 1,114 (22.0) | 4.14 | 3.47-4.94 | 2.20 | 1. 59–3.05 | ||
Not sure | 940 (11.5) | 1.91 | 1.48-2.47 | 1.44 | 1.00-2.07 | ||
Missing | 23 (13.0) | 2.20 | 0.46-10.53 | 1.41 | 0.31-6.35 | ||