Geometric mean cotinine concentrations and 95% CIs in non-smoking children by family socioeconomic classification (SEC) and family affluence scale (FAS), before and after smoke-free legislation in Scotland
| 2006 | 2007 | |||||||
| Family socio economic classification† | Mean (95% CI) cotinine concentration (ng/ml) | N (%) | Mean (95% CI) cotinine concentration (ng/ml) | N (%) | Absolute difference in mean cotinine concentration between 2006 and 2007 | |||
| Unadjusted | Adjusted* | Unadjusted | Adjusted* | Unadjusted | Adjusted* | |||
| Family SEC 1 | 0.19 (0.17 to 0.23) | 0.26 (0.23 to 0.29) | 708 (41.0) | 0.11 (0.09 to 0.13) | 0.16 (0.14 to 0.19) | 680 (42.7) | 0.08 | 0.10 |
| Family SEC 2 | 0.37 (0.31 to 0.44) | 0.37 (0.33 to 0.42) | 658 (38.1) | 0.21 (0.17 to 0.25) | 0.20 (0.18 to 0.23) | 556 (35.0) | 0.16 | 0.17 |
| Family SEC 3 | 0.56 (0.42 to 0.73) | 0.44 (0.37 to 0.52) | 199 (11.5) | 0.45 (0.34 to 0.59) | 0.27 (0.22 to 0.34) | 196 (12.3) | 0.15 | 0.17 |
| Family SEC 4 | 1.07 (0.79 to 1.45) | 0.66 (0.54 to 0.81) | 163 (9.4) | 0.84 (0.60 to 1.18) | 0.38 (0.31 to 0.46) | 162 (10.2) | 0.23 | 0.28 |
| Total | 0.33 (0.31 to 0.35) | 0.35 (0.32 to 0.37) | 1728 | 0.20 (0.18 to 0.22) | 0.20 (0.19 to 0.22) | 1594 | 0.13 | 0.15 |
| Family affluence | ||||||||
| High | 0.21 (0.18 to 0.24) | 0.28 (0.25 to 0.31) | 718 (34.1) | 0.11 (0.09 to 0.13) | 0.17 (0.15 to 0.19) | 655 (33.7) | 0.10 | 0.11 |
| Medium | 0.31 (0.26 to 0.36) | 0.34 (0.30 to 0.38) | 707 (33.6) | 0.19 (0.16 to 0.23) | 0.19 (0.17 to 0.22) | 665 (34.2) | 0.12 | 0.15 |
| Low | 0.66 (0.55 to 0.79) | 0.46 (0.41 to 0.52) | 679 (32.3) | 0.47 (0.38 to 0.58) | 0.29 (0.26 to 0.33) | 625 (32.1) | 0.19 | 0.17 |
| Total | 0.35 (0.32 to 0.39) | 0.36 (0.33 to 0.38) | 2104 | 0.21 (0.19 to 0.23) | 0.21 (0.19 to 0.24) | 1945 | 0.14 | 0.15 |
Children who are cotinine confirmed non-smokers; pupils who live in both, step or single parent families only.
↵* Adjusted for age and number of parents who smoke.
↵† Family socioeconomic classification: family SEC1=I professional occupations & II managerial and technical; SEC2=IIIN skilled non-manual & IIIM skilled manual; SEC3=IV partly skilled and V unskilled; SEC4=economically inactive.