Table 1. The criteria for high-risk individuals in different guidelines.

Institution	Age	Smoking history	Interval of LDCT
National Comprehensive Cancer Network (55)
Group 1	55–77	≥30 pack-year and either current smoker or former smoker quitting <15 years	Every year
Group 2	≥50	≥20 pack-year and with additional risk factors (other than second-hand smoke)	Every year
American Association for Thoracic Surgery (59)
Group 1	55–79	≥30 pack-year	Every year
Group 2	≥50	≥20 pack-year with a cumulative risk of developing lung cancer of 5%	Every year
USPSTF (60)	55–80	≥30 pack-year and either current smoker or former smoker quitting <15 years	Every year
American Cancer Society (61)	55–74	≥30 pack-year and either current smoker or former smoker quitting <15 years	Every year