Table 2.
Changes in cotinine level (expressed as mean and proportion) between 1978–80 and 1998–2000 among non-smokers: influence of age, social class and region (n = 1208).
|
Non smokers Q1–Q20 |
|||
|---|---|---|---|
| Unadjusted cotinine change Q1–Q20 | Mutually adjusted cotinine change Q1–Q20b | % change Q1–Q20c | |
| Grand mean | −1.47 (−1.57, −1.37) | −1.47 (−1.56, −1.37) | −87 |
| Age (years) at Q1 | |||
| 38–44 | −1.52 (−1.71, −1.34) | −1.50 (−1.68, −1.31) | −86 |
| 45–49 | −1.46 (−1.65, −1.28) | −1.49 (−1.67, −1.31) | −88 |
| 50–54 | −1.35 (−1.56, −1.15) | −1.37 (−1.57, −1.17) | −85 |
| 55–61 | −1.53 (−1.76, −1.30) | −1.52 (−1.74, −1.30) | −89 |
| P(trend)a | 0.735 | 0.740 | |
| Class at Q1 | |||
| I and II | −1.02 (−1.29, −0.76) | −1.13 (−1.39, −0.86) | −87 |
| II | −1.36 (−1.55, −1.17) | −1.37 (−1.55, −1.18) | −88 |
| III NM | −1.34 (−1.65, −1.04) | −1.36 (−1.66, −1.05) | −89 |
| III M | −1.93 (−2.51, −1.35) | −1.83 (−2.41, −1.25) | −88 |
| IV M | −1.58 (−1.74, −1.42) | −1.54 (−1.70, −1.38) | −85 |
| V M | −2.13 (−2.49, −1.78) | −2.10 (−2.46, −1.75) | −89 |
| Armed forces | −1.22 (−1.95, −0.50) | −1.32 (−2.05, −0.61) | −87 |
| P(trend)a | <0.001 | <0.001 | |
| Region at Q1 | |||
| South | −1.17 (−1.32, −1.01) | −1.22 (−1.37, −1.06) | −87 |
| Midlands | −1.87 (−2.13, −1.61) | −2.10 (−2.60, −1.60) | −93 |
| North | −1.59 (−1.74, −1.43) | −1.55 (−1.70, −1.39) | −86 |
| Scotland | −1.75 (−1.99, −1.50) | −1.73 (−1.97, −1.49) | −87 |
| P(trend)a | < 0.001 | < 0.001 | |
a
Trend tests all from separate linear regression models;
b
means adjusted for age, social class and region;
c
% change calculated as [adjusted geometric mean questionnaire 1 (Q1)—adjusted geometric mean Q20/adjusted geometric mean Q1] in 1208 men who were non-smokers at Q1 and Q20. Means adjusted for age, region and class only.