Self-reported tobacco use against urinary cotinine levels by tobacco use
| Self-reports | Urinary cotinine level | ||||||
| Cigarette smoking | Daily | Occasional | Any | ||||
| <50 ng/mL | ≥50 ng/mL | Total | κ: | 0.824 | 0.618 | 0.762 | |
| No | 455 | 35 | 490 | Sensitivity: | 80.2% | 70.8% | 86.6% |
| Occasional | 40 | 85 | 125 | Specificity: | 98.3% | 91.9% | 90.5% |
| Daily | 8 | 142 | 150 | PPV: | 94.7% | 68.0% | 82.5% |
| Total | 503 | 262 | 765 | NPV: | 92.9% | 92.9% | 92.9% |
| Snus use | Daily | Occasional | Any | ||||
| <50 ng/mL | ≥50 ng/mL | Total | κ: | 0.861 | 0.573 | 0.814 | |
| No | 455 | 35 | 490 | Sensitivity: | 83.6% | 59.3% | 86.8% |
| Occasional | 24 | 51 | 75 | Specificity: | 99.1% | 95.0% | 94.2% |
| Daily | 4 | 178 | 182 | PPV: | 97.8% | 68.0% | 89.1% |
| Total | 483 | 264 | 747 | NPV: | 92.9% | 92.9% | 92.9% |
| E-cigarette use | Any | ||||||
| <50 ng/mL | ≥50 ng/mL | Total | κ: | 0.576 | |||
| No | 455 | 35 | 490 | Sensitivity: | 60.7% | ||
| Occasional | 26 | 45 | 71 | Specificity: | 94.6% | ||
| Daily | 0 | 9 | 9 | PPV: | 67.5% | ||
| Total | 481 | 89 | 570 | NPV: | 92.9% | ||
Cigarette smoking: analysis including all self-reported cigarette smokers and all non-tobacco users.
Snus use: analysis including all self-reported snus users and all non-tobacco users.
E-cigarette use: analysis including all self-reported e-cigarette users and all non-tobacco users.
Daily: results from analyses excluding occasional tobacco users.
Occasional: results from analyses excluding daily tobacco users.
Any: results from analyses combining daily and occasional tobacco users.
κ: Cohen’s kappa coefficient.
NPV, negative predictive value; PPV, positive predictive value.