Table 4.
Death rates by duration of smoking among current male smokers of 20 cigarettes per day, Three‐Prefecture Study in Japan compared to the Cancer Prevention Study II in the USA
| Attained age (years) | Three‐Prefecture Duration* | CPS‐II Duration † | Rate ratio Duration † | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 30–39 | 40–49 | 50 + | 30–39 | 40–49 | 50 + | 30–39 | 40–49 | 50 + | |
| 50–59 | 42.0 | — | — | 143.1 | 267.3 | 483.1 | 0.29 | — | — |
| 60–69 | 119.0 | 170.1 | — | 215.7 | 452.3 | 848.5 | 0.55 | 0.38 | — |
| 70–79 | 180.5 | 142.1 | 590.6 | 455.9 | 702.1 | 1149.0 | 0.40 | 0.20 | 0.51 |
†
Duration of smoking was fixed at enrollment. ––, no lung cancer deaths observed (Three‐Prefecture cohort study), or no data available because of five or fewer deaths observed (Cancer Prevention Study II).