Table 1.
Summary statistics for urinary daily excretion of cotinine (μg/24 h) by sampling year.
| Sampling year | 1995 | 2000 | 2005 | 2010 | 2014 | 2015 | 2017 | 2018 | 2019 |
|---|---|---|---|---|---|---|---|---|---|
| N total | 55 | 57 | 58 | 55 | 57 | 58 | 57 | 59 | 54 |
| N > LLOQ | 45 (82%) | 47 (82%) | 36 (62%) | 26 (47%) | 26 (46%) | 20 (34%) | 16 (28%) | 15 (25%) | 13 (24%) |
| GM | 1.6 | 1.1 | 0.8* | 0.4*** | 0.4*** | 0.3*** | 0.4*** | 0.3*** | 0.3*** |
| CI1 | 0.5–2.7 | <LLOQ-2.2 | <LLOQ-2.0 | – | – | – | – | – | – |
| Median1 | 2.1 | 1.1 | 0.5 | – | – | – | – | – | – |
| P95 | 11.9 | 15.6 | 10.9 | 6.7 | 2.6 | 6.0 | 9.2 | 8.6 | 3.5 |
| Max | 17.4 | 19.3 | 14.4 | 23.4 | 4.5 | 26.2 | 15.1 | 17.5 | 13.3 |
GM: geometric mean; CI: 95% confidence interval of geometric mean, P95: 95th percentile; Max: Maximum; Significance test: Mann-Whitney-U test, compared to 1995: *p < 0.05, **p < 0.01, ***p < 0.001. 1 CI and median not calculated, if number of samples below LLOQ >50%.