Table 1.
Factors associated with undetectable cotinine levels in nonsmoking adults and impacts of smokefree legislation, Health Survey for England, 1998–2008.
| Sample (n) | Percent with undetectable cotinine | Unadjusted OR,aunivariate regression | Adjusted OR,amultivariate regressionb | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Predictor variable | Levels in predictor variable | Estimate (95% CI) | Estimate (95% CI) | |||||||||
| Smokefree legislation | Before 1 July 2007 | — | ||||||||||
| After 1 July 2007 | 1.52 | (1.29, 1.79)** | ||||||||||
| Age (years) | 16–29 | 4,352 | 20.7 | — | — | |||||||
| 30–44 | 8,087 | 27.7 | 1.47 | (1.33, 1.62)** | 1.56 | (1.41, 1.73)** | ||||||
| 45–59 | 8,031 | 29.2 | 1.58 | (1.44, 1.75)** | 1.76 | (1.59, 1.95)** | ||||||
| ≥ 60 | 9,815 | 33.5 | 1.93 | (1.75, 2.13)** | 2.21 | (1.99, 2.46)** | ||||||
| Sex | Male | 13,570 | 27.1 | — | — | |||||||
| Female | 16,715 | 30.0 | 1.15 | (1.10, 1.21)** | 1.23 | (1.17, 1.30)** | ||||||
| Social class of head of household | I and II (professional, managerial, and technical) | 13,546 | 32.9 | — | — | |||||||
| III (skilled nonmanual and manual) | 11,333 | 26.1 | 0.72 | (0.68, 0.77)** | 0.81 | (0.76, 0.87)** | ||||||
| IV and V (semiskilled and unskilled manual) | 4,719 | 23.3 | 0.62 | (0.57, 0.68)** | 0.71 | (0.65, 0.79)** | ||||||
| Education level of individual | Higher education qualification | 9,518 | 32.6 | — | — | |||||||
| School level (or other) qualifications | 13,183 | 26.9 | 0.76 | (0.72, 0.81)** | 0.92 | (0.86, 0.98)* | ||||||
| No qualification | 7,570 | 27.0 | 0.77 | (0.71, 0.82)** | 0.81 | (0.74, 0.89)** | ||||||
| Ethnicity | Whitec | 28,225 | 28.7 | — | — | |||||||
| Black or Asian | 1,638 | 28.7 | 1.00 | (0.88, 1.15) | 0.94 | (0.81, 1.09) | ||||||
| Someone smokes most days inside the home? | Yesc | 2,858 | 4.4 | — | — | |||||||
| No | 27,420 | 31.3 | 9.90 | (8.09, 12.1)** | 8.11 | (6.57, 10.0)** | ||||||
| —, indicates baseline category. aCompares the ratio of the odds between a category and the baseline category. These estimates were derived by exponentiating the regression coefficients from the regression model. Regression results rounded to two decimal places.bModel includes a linear and quadratic term for time. cIncludes qualifications obtained outside the United Kingdom, Nursery Nurse Examination Board, and Clerical and Commercial qualification. *p < 0.05 and **p < 0.01 indicates a significant difference from the baseline category. | ||||||||||||