Risk factor	Odds ratio for malignant solitary pulmonary nodule
Veterans Affairs Model (for nodules > 7 mm in diameter)
Current or past smoking	7.9
Patient age (per 10-year increment)	2.2
Nodule diameter (per mm)	1.1
Time since quitting smoking (per 10-year increment)	0.6
Mayo Clinic Model (for nodules > 4 mm in diameter)
History of extrathoracic cancer	3.8
Spiculated morphology	2.8
Current or past smoking	2.2
Upper lung location	2.2
Nodule diameter (per mm)	1.14
Patient age (years)	1.04