Table 1 Estimated duration of Lead time of lung cancer derived from randomized controlled trials of screening by chest radiography (CR)
Trial and authors | Study population (n) | Prevalence of lung cancers per 1000 at T0 | Average duration of screening (years) | Average annual incidence of confirmed screen-detected and interval lung cancers per 1000 during screening | Lead time (years) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Intervention | Control | Intervention (a) | Control (b) | Intervention, screen-detected (c) | Intervention, interval (d) | Control, screen-detected (e) | Control, interval (f) | a/(c + d) | a/(e + f) | ||
North London: Brett 1968[7]a | 29,723 | 25,311 | 1.0 | 0.8 | 3 | 0.7 | 0.4 | Not applicable | 0.8 | 0.9 | 1.3 |
4618 | 4593 | 6.8 | 6.8 | 6 | 2.6 | 1.9 | Not applicable | 3.2 | 1.5 | 2.1 | |
John Hopkins: Frost et al. 1984 [10]; Doria-Rose et al. 2009 [11]c | 5226 | 5161 | 5.4 | 7.8 | 7.2 | 2.6 | 2.7 | 3.6 | 2.9 | 1.0 | 0.8 |
Memorial Sloan Kettering: Melamed et al. 1984 [12]; Doria-Rose et al. 2009 [11]c | 4968 | 5072 | 4.2 | 4.6 | 7.2 | 2.1 | 2.0 | 2.4 | 2.2 | 1.0 | 0.9 |
The Erfurt Trial: Wilde 1989 [13]d | 41,532 | 102,348 | 0.8 | 0.7 | 6 | 0.6 | 0.8 | 0.2 | 0.8 | 0.6 | 0.8 |
Chech Lung Cancer Detection Trial: Kubik et al. 1990 [14], 2000 [15]e | 3171 | 3174 | 3.0 | 3.0 | 3 | 2.9 | 1.1 | Not applicable | 2.0 | 0.8 | 1.5 |
PLCO: Oken et al. 2011 [16] f | 77,445 | 77,456 | 2.3 | 1.4 | 3 | 1.3 | 0.9 | Not applicable | 1.7 | 1.0 | 1.4 |