Table 3.
Means, 95% Confidence Intervals, and Bias for Spiked Pools with Known Concentrations
| Pool | Number of Labs | N | Nicotine, ng/mL | 95% CI | Target | Mean % Bias | Range |
|---|---|---|---|---|---|---|---|
| F | 8 | 48 | 295.9 | 286.7 – 305 | 286 | 3.462 | − 8.5 to 14.8% |
| G | 8 | 48 | 699.2 | 676.2 – 722.4 | 714 | −2.07 | − 13.3 to 12.8% |
| Pool | Number of Labs | N | Cotinine, ng/mL | 95% CI | Target | Mean % Bias | Range |
|---|---|---|---|---|---|---|---|
| F | 9 | 54 | 610.2 | 596.1 – 624.3 | 605 | 0.860 | − 14.5 to 6.0% |
| G | 8 | 48 | 1729.3 | 1673.1 – 1785.5 | 1729 | 0.017 | − 24.5 to 9.1% |
| Pool | Number of Labs | N | Hydroxycotinine, ng/mL | 95% CI | Target | Mean % Bias | Range |
|---|---|---|---|---|---|---|---|
| F | 7 | 42 | 1079.2 | 1052.9 – 1105.1 | 1066 | 1.238 | − 11.7 to 9.9% |
| G | 7 | 42 | 4046.8 | 3948.1 – 4145.5 | 3999 | 1.195 | − 10.2 to 12.7% |
One outlier laboratory (#11) was omitted from these calculations