Table A1.

Association Between Smoking Status and Cigarettes Smoked per Day and Risk of a Second Primary Smoking-Associated Cancer Among Survivors of Lung (stage I), Bladder, Kidney, and Head/Neck Cancers, Including Follow-Up Time and Event Occurring Within 30 Days of Diagnosis

Smoking Status	Stage I Lung		Bladder		Kidney		Head/Neck Cancer
	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI
Never	1.00	Referent	1.00	Referent	1.00	Referent	1.00	Referent
Former
< 20 cig/d	0.56	0.17 to 1.88	1.94	1.25 to 2.99	1.95	1.11 to 3.42	1.63	0.91 to 2.91
≥ 20 cig/d*	1.09	0.39 to 3.05	2.22	1.45 to 3.40	3.86	2.24 to 6.65	3.08	1.81 to 5.25
Current
< 20 cig/d	2.05	0.75 to 5.89	2.12	1.96 to 4.95	3.45	1.75 to 6.78	2.90	1.65 to 5.09
≥ 20 cig/d*	2.08	0.73 to 5.59	4.10	2.54 to 6.62	5.01	2.49 to 10.1	4.84	2.80 to 8.36
P trend†	.04		< .001		.001		< .001

NOTE. Adjusted for age, sex, race, education, body mass index, cohort, time from baseline to first cancer, and follow-up time. Excludes Alpha-Tocopherol, Beta-Carotene Cancer Prevention study, given that this cohort was limited to current smokers.

Abbreviations: cig/d, cigarettes per day; HR, hazard ratio.

^*Cigarettes per day was collected as a categorical variable in National Institutes of Health–AARP Diet and Health Study; Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial; and Agricultural Health Study. The maximum number of cigarettes smoked per day in the Iowa Women's Health Study was as follows: lung (stage I): 60; bladder: 40; kidney: 40; head and neck: 40.

^†P trends across joint categories of smoking status and intensity categories were estimated by including the categorical exposure variable in the model as a continuous variable.