Table 3.

HRs for effect of exposures in current and former smokers estimated in the training set and their predictive value in the test set

	HR (95% CI)		P		P for improvement in AUC		tdNRI
							Change		P
Covariate	Current	Former	Current	Former	Current	Former	Current	Former	Current	Former
Sex: female 1, male 0.	1.35 (1.16–1.57)	1.2 (0.91–1.59)	0.000126	0.194	−	0.885	−0.346	−0.321	0.99	0.937
BMI	0.963 (0.946–0.98)	0.96 (0.929–0.992)	3.7 × 10⁻⁵	0.0148	−	−	−0.0709	−0.206	0.687	0.82
Education level (greater than high school)	0.944 (0.751–1.19)	0.436 (0.275–0.691)	0.62	0.000418	0.243	−	0.235	−0.0763	0.01	0.637
Hay fever	0.593 (0.335–1.05)	0.901 (0.494–1.64)	0.0728	0.734	+	+	0.233	0.12	0.139	0.366
Asthma	0.85 (0.546–1.32)	1.58 (0.961–2.6)	0.474	0.071	+	+	0.0437	−0.0127	0.346	0.504
Family history of cancer	1.27 (0.758–2.11)	1.23 (0.694–2.16)	0.368	0.484	+	+	−0.217	−0.235	0.9	0.845
Chr15q25	1.13 (1.01–1.27)	1.14 (0.933–1.38)	0.0336	0.202	−	0.726	0.309	0.406	0.381	0.23
Chr5p15	0.954 (0.845–1.08)	1.06 (0.865–1.3)	0.442	0.572	0.765	0.885	1.3	−0.495	0.067	0.808
Occupational exposures
Silica	0.893 (0.602–1.33)	0.851 (0.349–2.07)	0.574	0.722	+	+	−0.0252	−0.0907	0.684	0.945
PAH	0.988 (0.808–1.21)	0.869 (0.586–1.29)	0.906	0.485	0.671	−	0.0177	−0.194	0.428	0.871
Metal	0.961 (0.794–1.16)	1.23 (0.866–1.74)	0.68	0.249	−	0.308	−0.385	0.281	0.996	0.06
Asbestos	0.943 (0.775–1.15)	1.05 (0.738–1.49)	0.558	0.784	−	0.603	−0.24	0.296	0.986	0.029

NOTE: Exposure effects are conditional on lifetime exposure to cigarette smoke. P value for improvement in AUC and tdNRI compares predictive performance of model with and without covariate (tdNRI P values were calculated by permutation). AUC P values are not shown for covariates whose inclusion decreased the AUC (denoted by −) and there were fewer than 5 exposed cases (denoted by +).