Table 1 Main characteristics and results of the National Lung Screening Trial (NLST), 33 sites in the United States
From: Why and how would we implement a lung cancer screening program?
| Â | Intervention arm | Control arm |
|---|---|---|
Screening test | Low dose computed tomography | Chest X-ray |
Entry criteria | Â | |
 Health status | Asymptomatic | |
 Age, years | 55 to 74 | |
 Smoking status | ≥30 pack-years or had been smokers within the previous 15 years | |
Screening interval | Annually | |
Screening duration | 3Â years | |
Number of participants randomized | 26,722 | 26,732 |
 Male, N (%) | 15,770 (59.0) | 15,762 (59.0) |
 Number of participants aged ≥65 years (%) | 7,110 (26.6) | 7,110 (26.6) |
 Number of former smokers (%) | 13,860(51.9) | 13,832 (51.7) |
 Number of current smokers (%) | 12,862 (48.1) | 12,900 (48.3) |
Year 1 (baseline) | Â | Â |
 Number screened | 26,309 | 26,035 |
 Positive results (%) | 7191 (27.3) | 2387 (9.2) |
 Complete diagnostic follow-up (%) | 7049 (98.0) | 2348 (98.3) |
 Thoracotomy (%) | 197 (2.8) | 96 (4.1) |
 Had lung cancer (%) | 270 (3.8) | 136 (5.7) |
Year 2 | Â | Â |
 Number screened | 24,715 | 24,089 |
 Positive results (%) | 6901 (27.9) | 1482 (6.2) |
 Complete diagnostic follow-up (%) | 6740 (97.7) | 1456 (98.2) |
 Thoracotomy (%) | 148 (2.2) | 44 (3.0) |
 Had lung cancer (%) | 168 (2.4) | 65 (4.4) |
Year 3 | Â | Â |
 Number screened | 24,102 | 23,346 |
 Positive results (%) | 4054 (16.8) | 1174 (16.8) |
 Complete diagnostic follow-up (%) | 3913 (96.5) | 1149 (97.9) |
 Thoracotomy (%) | 164 (4.2) | 44 (3.8) |
 Had lung cancer (%) | 211 (5.2) | 78 (6.6) |
Overall (Year 1–3) |  |  |
 Number of screening tests | 75,126 | 73,470 |
 Positive results (%) | 18,146 (16.8) | 5043(16.8) |
 Complete diagnostic follow-up (%) | 17,702 (97.5) | 4953 (98.2) |
 Thoracotomy (%) | 509 (2.9) | 184 (3.7) |
 Had lung cancer (%) | 649 (3.6) | 279 (5.5) |
 Death within 60 days after most invasive diagnositc procedure | 10 | 11 |
 Person-years | 144,103 | 143,368 |
 Lung cancer death | 356 | 443 |
 Rate per 100,000 person-years | 247/100,000 | 309/100,000 |
 Overall death | 1877 | 1998 |
 Rate per 100,000 person-years | 1302 /100,000 | 1394/100,000 |