Characteristics of included studies
| Trial name | Population characteristics | Intervention (screening interval months/rounds) | Total subjects (intervention/control arm subjects) | Control | Follow-up time after last screen years | Participation rate | Contamination rate |
| DLCST | Men and women aged 50–70 years, smokers and former smokers ≥20 pack-years Former smokers must have quit <10 years prior | LDCT (12/5) | 4104 (2052/2052) | Usual care | 5 | 95.5% | 20.3% |
| ITALUNG | Men and women aged 55–69 years, smokers and former smokers ≥20 pack-years in past 10 years | LDCT (12/4) | 3206 (1613/1593) | Usual care | 5 | 81% | Not reported |
| LUSI | Men and woman aged 50–69 years, smokers and former smokers (cessation <10 years) with ≥25 years of smoking ≥15 cigarettes a day or 30 years of smoking 10 cigarettes per day | LDCT (12/5) | 4052 (2029/2023) | Usual care | 3 | >90% | 8.7% |
| MILD | Men and women aged 49–75 years, current or former (cessation <10 years) ≥20 pack-years | LDCT (12 or 24/6 or 3) Median duration of screening was 6.2 years | 4099 (2376/1723) | Usual care | The follow-up since last screening round is unclear | 95.1% in the biennial and 96.1% in the annual LDCT group | 1.2% |
| NELSON | Men aged 50–74 years, current or former smokers (who had quit ≤10 years ago) who had smoked >15 cigarettes a day for >25 years or >10 cigarettes a day for >30 years | LDCT (12, 24, 30/4) | 13 195 (6583/6612) | Usual care | 4.5 | 85.8% in total (lowest at round 4 with 67.4% and highest at round 1 with 95.8%) | Not reported |