ORs (95% CI) for secondhand smoke (SHS) exposure in 2008 compared with 2006 by the place of exposure
| Year 2006 | Year 2008 | ||
| Place of SHS exposure | Crude ORs | Adjusted ORs* | |
| At home | |||
| 1–3 days | 1 | 1.39 (1.14 to 1.69) | 1.51 (1.12 to 2.03) |
| 4–7 days | 1 | 1.55 (1.28 to 1.87) | 1.58 (1.24 to 2.03) |
| Any | 1 | 1.47 (1.28 to 1.69) | 1.56 (1.25 to 1.92) |
| Outside home | |||
| 1–3 days | 1 | 1.41 (1.25 to 1.60) | 1.45 (1.12 to 1.89) |
| 4–7 days | 1 | 2.01 (1.67 to 2.42) | 2.01 (1.49 to 2.71) |
| Any | 1 | 1.57 (1.41 to 1.75) | 1.60 (1.26 to 2.03) |
| Anywhere | |||
| 1–3 days | 1 | 1.40 (1.23 to 1.60) | 1.39 (1.08 to 1.79) |
| 4–7 days | 1 | 1.68 (1.46 to 1.92) | 1.71 (1.37 to 2.14) |
| Any | 1 | 1.53 (1.38 to 1.69) | 1.54 (1.25 to 1.89) |
↵* Adjusted for sex, age, grade, place of birth, parental smoking status and clustering effect of schools.