Table 2. Change in the geometric means of salivary cotinine concentrations (ng/mL) before (2004–05) and after (2011–12) the smoke-free legislation, Barcelona, Spain; results are stratified according to socio-demographic variables.
| Before legislation | After legislation | Percentage of change* (95% CI) | |||
| N | GM (GSD) (ng/mL) | N | GM (GSD) (ng/mL) | ||
| All subjects | 724 | 0.93 (4.01) | 878 | 0.12 (3.12) | 87.6 (76.7–102.0) |
| Sex | |||||
| Men | 296 | 1.11 (3.65) | 380 | 0.12 (2.91) | 89.4 (80.6–102.1) |
| Women | 428 | 0.82 (4.22) | 498 | 0.12 (3.28) | 86.1 (74.4–102.7) |
| Age (years) ** | |||||
| 16–44 | 236 | 1.00 (3.66) | 361 | 0.12 (3.09) | 88.0 (78.1–102.7) |
| 45–64 | 234 | 0.82 (4.17) | 254 | 0.13 (3.18) | 85.4 (73.9–104.1) |
| ≥65 | 251 | 0.98 (4.19) | 263 | 0.11 (3.10) | 89.2 (80.6–102.9) |
| Educational level ** | |||||
| Less than primary and primary | 342 | 0.87 (4.16) | 236 | 0.12 (3.27) | 86.1 (79.4–103.5) |
| Secondary | 132 | 0.97 (3.95) | 341 | 0.14 (3.28) | 85.2 (73.7–104.3) |
| University | 249 | 0.98 (3.83) | 300 | 0.10 (2.75) | 90.2 (82.2–102.1) |
GM: Geometric mean.
GSD: Geometric standard deviation.
*Based on the adjusted geometric mean derived from a generalized linear model that included all the variables in the table.
**The figures do not sum the total because of missing values.