Table 2.
Descriptive Statistics and ROC Outcome for Gender and Race
| Sample | CO level, M (SD) | CPD, M (SD) | AUC (95% CI) | ROC outcome (CO = 3 ppm) | ||||
|---|---|---|---|---|---|---|---|---|
| Cot + | Cot − | Cot + | Cot − | Sens | Spec | Eff | ||
| Total | ||||||||
| N = 662 | 16.46 | 2.57 | 15.01 | 1.64 | .956 | .981 | .811 | .971 |
| P = .944 | (10.26) | (3.51) | (9.22) | (3.95) | (.922–.991) | |||
| Gender | ||||||||
| Male | ||||||||
| n = 446 | 16.69 | 2.23 | 15.06 | 1.90 | .970 | .988 | .864 | .982 |
| P = .951 | (9.36) | (2.58) | (9.65) | (4.87) | (.943–.998) | |||
| Female | ||||||||
| n = 216 | 18.53 | 3.07 | 14.91 | 1.27 | .937 | .965 | .733 | .949 |
| P = .931 | (10.99) | (4.60) | (8.29) | (2.22) | (.869–1.000) | |||
| Race | ||||||||
| Black | ||||||||
| n = 418 | 16.39* | 2.83 | 12.18** | 2.30 | .943 | .99 | .783 | .969 |
| P = .945 | (9.99) | (3.96) | (7.32) | (4.743) | (.887–.999) | |||
| White | ||||||||
| n = 229 | 18.95* | 1.67 | 18.62** | 0.50 | .985 | .98 | .917 | .978 |
| P = .948 | (9.71) | (1.50) | (7.89) | (1.45) | (.985–1.000) | |||
Note. ROC = receiver operating characteristics; CO level = carbon monoxide level in ppm; COT= cotinine; CPD = cigarettes smoked per day; AUC = area under the curve; CI = confidence interval; sens = sensitivity (i.e., proportion of smokers accurately identified; positive outcome); spec = specificity (i.e., proportion of nonsmokers accurately identified; negative outcome); eff = efficiency (i.e., weighted average of sensitivity and specificity taking into account disease prevalence); P = prevalence of smoking within sample.
*Significantly different at p < .002.
**Significantly different at p < .001.