P value of 0.0468 as shown when the results were compared with those of ELCAP study, however, no significant differences were found n comparison with other 3 series from within and outside China.

• 本组肺癌筛查结果与ELCAP分析显示P=0.；0468，与国内外其它3组比较差异无统计学意义(P>0