Table 4.
Performance of indicators and combinations with liquid chromatography-tandem mass spectrometry (LCMSMS) urine and saliva cotinine as reference measures.
| LCMSMS specimen |
LCMSMS cotinine cut-off (ng/ml) |
Biochemical indicator | Biochemical indicator cut-off |
True positives |
True negatives |
False positives |
False negatives |
Sensitivity (%) |
Specificity (%) |
Efficiency (%) |
Positive likelihood ratio |
Negative likelihood ratio |
Positive predictive value (%) |
Negative predictive value (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Urine | ≥0.2 | Self-report | NA | 90 | 26 | 0 | 56 | 61.6 | 100.0 | 67.4 | NA | 0.38 | 100.0 | 31.7 |
| Urine | ≥25 | Self-report | NA | 89 | 78 | 1 | 4 | 95.7 | 98.7 | 97.1 | 75.60 | 0.04 | 98.9 | 95.1 |
| Urine | ≥100 | Self-report | NA | 89 | 81 | 1 | 1 | 98.9 | 98.8 | 98.8 | 81.09 | 0.01 | 98.9 | 98.8 |
| Saliva | ≥0.2 | Self-report | NA | 88 | 63 | 2 | 19 | 82.2 | 96.9 | 87.8 | 26.70 | 0.18 | 97.8 | 76.8 |
| Saliva | ≥10 | Self-report | NA | 88 | 81 | 2 | 1 | 98.9 | 97.6 | 98.3 | 41.03 | 0.01 | 98.7 | 98.8 |
| Urine | ≥0.2 | Breath CO | ≥5 | 86 | 25 | 1 | 60 | 58.9 | 96.2 | 64.5 | 15.32 | 0.43 | 98.9 | 29.4 |
| Urine | ≥25 | Breath CO | ≥5 | 86 | 78 | 1 | 7 | 92.5 | 98.7 | 95.3 | 73.05 | 0.08 | 98.9 | 91.8 |
| Urine | ≥100 | Breath CO | ≥5 | 85 | 80 | 2 | 5 | 94.4 | 97.6 | 94.8 | 38.72 | 0.06 | 97.7 | 94.1 |
| Saliva | ≥0.2 | Breath CO | ≥5 | 85 | 63 | 2 | 22 | 79.4 | 96.9 | 86.1 | 25.82 | 0.21 | 97.7 | 74.1 |
| Saliva | ≥10 | Breath CO | ≥5 | 84 | 80 | 3 | 5 | 94.4 | 96.4 | 95.3 | 26.11 | 0.06 | 96.6 | 94.1 |
| Urine | ≥0.2 | Urine NicAlert | ≥3 | 84 | 25 | 1 | 62 | 57.5 | 96.2 | 63.3 | 14.96 | 0.44 | 98.8 | 28.7 |
| Urine | ≥25 | Urine NicAlert | ≥3 | 84 | 78 | 1 | 9 | 90.3 | 98.7 | 94.2 | 71.35 | 0.10 | 98.8 | 89.7 |
| Urine | ≥100 | Urine NicAlert | ≥3 | 83 | 80 | 2 | 7 | 92.2 | 97.6 | 94.8 | 37.81 | 0.08 | 97.7 | 92.0 |
| Saliva | ≥0.2 | Saliva NicAlert | ≥1 | 71 | 55 | 10 | 36 | 66.4 | 84.6 | 73.3 | 4.31 | 0.40 | 87.7 | 60.4 |
| Saliva | ≥10 | Saliva NicAlert | ≥1 | 68 | 70 | 13 | 21 | 76.4 | 84.3 | 80.2 | 4.88 | 0.28 | 84.0 | 77.0 |
| Urine | ≥0.2 | Self-report/breath CO | NA/≥5 | 91 | 25 | 1 | 55 | 62.3 | 96.2 | 67.4 | 16.21 | 0.39 | 98.9 | 31.3 |
| Urine | ≥25 | Self-report/breath CO | NA/≥5 | 90 | 77 | 2 | 3 | 96.8 | 97.5 | 97.1 | 38.23 | 0.03 | 97.8 | 96.3 |
| Urine | ≥100 | Self-report/breath CO | NA/≥5 | 89 | 79 | 3 | 1 | 98.9 | 96.3 | 97.7 | 27.03 | 0.01 | 96.7 | 98.8 |
| Saliva | ≥0.2 | Self-report/breath CO | NA/≥5 | 89 | 62 | 3 | 18 | 83.2 | 95.4 | 87.8 | 18.02 | 0.18 | 96.7 | 77.5 |
| Saliva | ≥10 | Self-report/breath CO | NA/≥5 | 84 | 79 | 4 | 5 | 94.4 | 95.2 | 94.8 | 19.58 | 0.06 | 95.5 | 94.1 |
| Urine | ≥0.2 | Self-report/urine NicAlert | NA/≥3 | 91 | 25 | 1 | 55 | 62.3 | 96.2 | 67.4 | 16.21 | 0.39 | 98.9 | 31.3 |
| Urine | ≥25 | Self-report/urine NicAlert | NA/≥3 | 90 | 77 | 2 | 3 | 96.8 | 97.5 | 97.1 | 38.23 | 0.03 | 97.8 | 96.3 |
| Urine | ≥100 | Self-report/urine NicAlert | NA/≥3 | 89 | 79 | 3 | 1 | 98.9 | 96.3 | 97.7 | 27.03 | 0.01 | 96.7 | 98.8 |
| Saliva | ≥0.2 | Self-report/saliva NicAlert | NA/≥1 | 92 | 55 | 10 | 15 | 86.0 | 84.6 | 85.5 | 5.59 | 0.17 | 90.2 | 78.6 |
| Saliva | ≥10 | Self-report/saliva NicAlert | NA/≥1 | 89 | 70 | 13 | 0 | 100.0 | 84.3 | 92.4 | 6.39 | 0.00 | 87.3 | 100.0 |
| Urine | ≥0.2 | Breath CO/urine NicAlert | ≥5/≥3 | 90 | 24 | 2 | 56 | 61.6 | 92.3 | 66.3 | 8.01 | 0.42 | 97.8 | 30.0 |
| Urine | ≥25 | Breath CO/urine NicAlert | ≥5/≥3 | 90 | 77 | 2 | 3 | 96.8 | 97.5 | 97.1 | 38.23 | 0.03 | 97.8 | 96.3 |
| Urine | ≥100 | Breath CO/urine NicAlert | ≥5/≥3 | 88 | 79 | 2 | 3 | 96.7 | 97.5 | 97.1 | 39.16 | 0.03 | 97.8 | 96.3 |
| Saliva | ≥0.2 | Breath CO/saliva NicAlert | ≥5/≥1 | 91 | 54 | 11 | 16 | 85.1 | 83.1 | 84.3 | 5.03 | 0.18 | 89.2 | 77.1 |
| Saliva | ≥10 | Breath CO/saliva NicAlert | ≥5/≥1 | 87 | 68 | 15 | 2 | 97.8 | 81.9 | 90.1 | 5.41 | 0.03 | 85.3 | 97.1 |
| Urine | ≥0.2 | Urine NicAlert/saliva NicAlert | ≥3/≥1 | 100 | 24 | 2 | 46 | 68.5 | 92.3 | 72.1 | 8.90 | 0.34 | 98.0 | 34.1 |
| Urine | ≥25 | Urine NicAlert/saliva NicAlert | ≥3/≥1 | 90 | 67 | 12 | 3 | 96.8 | 84.8 | 91.3 | 6.37 | 0.04 | 88.2 | 95.7 |
| Urine | ≥100 | Urine NicAlert/saliva NicAlert | ≥3/≥1 | 88 | 68 | 14 | 2 | 97.8 | 82.9 | 90.7 | 5.73 | 0.03 | 86.3 | 97.1 |
| Saliva | ≥0.2 | Urine NicAlert/saliva NicAlert | ≥3/≥1 | 92 | 55 | 10 | 15 | 86.0 | 84.6 | 85.5 | 5.59 | 0.17 | 90.2 | 78.6 |
| Saliva | ≥10 | Urine NicAlert/saliva NicAlert | ≥3/≥1 | 87 | 70 | 14 | 1 | 98.8 | 83.3 | 91.3 | 5.93 | 0.01 | 86.1 | 98.6 |
True positive: LCMSMS smoker and indicator smoker. True negative: LCMSMS non-smoker and indicator non-smoker. False positive: LCMSMS non-smoker and indicator smoker. False negative: LCMSMS smoker and indicator non-smoker. CO: carbon monoxide; NA: not applicable. NicAlert is a Registered Trademark.