Patient age (years)  | 
        2006  | 
        2008  | 
        p  | 
       
      
        35-49 years  | 
        0/5 (0%)  | 
        8/16 (50.0%)  | 
        0.11  | 
       
      
        50-64 years  | 
        2/3 (66.6%)  | 
        15/25 (60.0%)  | 
        1.00  | 
       
      
        ≥ 65 years                           | 
        4/9 (44.4%)  | 
        18/31 (58.1%)  | 
        0.70  | 
       
      
        Nodule diameter (mm)  | 
           | 
           | 
           | 
       
      
        ≤ 4mm  | 
        3/6 (50.0%)  | 
        20/36 (55.6%)  | 
        1.00  | 
       
      
        > 4-6mm  | 
        0/4 (0%)  | 
        8/16 (50.0%)  | 
        0.12  | 
       
      
        > 6-8mm  | 
        None.  | 
        5/7 (71.4%)  | 
        N/A  | 
       
      
        > 8mm  | 
        3/7 (42.9%)  | 
        8/13 (61.5%)  | 
        0.64  | 
       
      |