Table 4.

Validity, safety and concordance of self-reported smoking in comparison with the determination of urine cotinine test.

	Estimation 95% CI	Estimation 95% CI	Estimation 95% CI	Estimation 95% CI
Prevalence	75.41% 66.63-82.55	72.95% 64.02-80.40	65.29% 56.03-73.56	64.17% 54.85-72.57
Correctly diagnosed	95.08% 89.15-97.99	97.54% 92.44-99.36	96.69% 91.24-98.94	96.67% 91.17-98.93
Sensitivity	93.48% 85.80-97.32	96.63% 89.77-99.13	96.20% 88.55-99.01	94.81% 86.53-98.32
Specificity	100% 85.87-99.70	100% 87.02-99.72	97.62% 85.90-99.88	100% 89.79-99.79
PPV	100% 94.67-99.89	100% 94.67-99.89	98.70% 91.99-99.93	100% 93.77-99.88
NPV	83.33% 66.53-93.04	91.67% 76.41-97.82	93.18% 80.29-98.22	91.49% 78.73.97.24
Positive likelihood ratio	--	--	40.41 5.82-280.33	--
Negative likelihood ratio	0.07 0.03-0.14	0.03 0.01-0.10	0.04 0.01-0.12	0.05 0.02-0.13
Kappa index	0.876	0.939	0.928	0.929

PPV: positive predictive value; NPV: negative predictive value