Table 2.
Lung cancer mortality rates (per 100 000 person‐years), mortality rate differences and rate ratios among male ex‐smokers who started smoking at age 18–22 years by age at quitting smoking and attained age (attained age, 40–89 years)
| Age at quitting smoking (years) | Attained age (years) | Person‐years | No. lung cancer deaths | Lung cancer mortality rate (95% CI) | Crude mortality rate difference compared with current smokers (95% CI) | Mortality rate ratio 1 † compared with current smokers (95% CI) | Mortality rate ratio 2 ‡ compared with current smokers (95% CI) |
|---|---|---|---|---|---|---|---|
| 40–49 | 40–49 | 9087.5 | 1 | 11.0 (0.0–32.6) | −3.5 (−26.1–19.2) | 0.78 (0.10–5.86) | 0.79 (0.10–5.92) |
| 50–59 | 31 465.2 | 4 | 12.7 (0.3–25.2) | −34.4 (−50.5 to −18.2) | 0.27 (0.10–0.74) | 0.25 (0.09–0.68) | |
| 60–69 | 19 530.9 | 9 | 46.1 (16.0–76.2) | −154.7 (−193.5 to −115.9) | 0.23 (0.12–0.44) | 0.21 (0.11–0.41) | |
| 70–79 | 5183.7 | 2 | 38.6 (0.0–92.1) | −501.5 (−586.1 to −417.0) | 0.07 (0.02–0.29) | 0.07 (0.02–0.27) | |
| 80–89 | 744.2 | 3 | 403.1 (0.0–859.3) | −560.7 (−1072.0 to −49.5) | 0.42 (0.13–1.33) | 0.33 (0.10–1.08) | |
| 50–59 | 50–59 | 7643.8 | 5 | 65.4 (8.1–122.8) | 18.3 (−39.9–76.6) | 1.40 (0.57–3.46) | 1.33 (0.54–3.28) |
| 60–69 | 29 008.9 | 33 | 113.8 (74.9–152.6) | −87.0 (−132.9 to −41.1) | 0.57 (0.40–0.82) | 0.51 (0.35–0.74) | |
| 70–79 | 10 612.0 | 25 | 235.6 (143.2–327.9) | −304.5 (−417.8 to −191.3) | 0.44 (0.29–0.66) | 0.39 (0.26–0.60) | |
| 80–89 | 1146.8 | 4 | 348.8 (7.0–690.6) | −615.0 (−1027.5 to −202.6) | 0.36 (0.13–1.00) | 0.30 (0.11–0.83) | |
| 60–69 | 60–69 | 7082.8 | 11 | 155.3 (63.5–247.1) | −45.5 (−140.4–49.5) | 0.81 (0.44–1.48) | 0.74 (0.40–1.37) |
| 70–79 | 13 393.2 | 43 | 321.1 (225.1–417.0) | −219.1 (−335.3 to −102.9) | 0.60 (0.43–0.82) | 0.54 (0.39–0.76) | |
| 80–89 | 2188.8 | 9 | 411.2 (142.5–679.8) | −552.7 (−906.8 to −198.5) | 0.43 (0.21–0.86) | 0.35 (0.17–0.72) | |
| 70–79 | 70–79 | 1881.1 | 16 | 850.6 (433.8–1267.3) | 310.4 (−111.5–732.3) | 1.58 (0.95–2.62) | 1.45 (0.87–2.42) |
| 80–89 | 1670.3 | 21 | 1257.3 (719.5–1795.0) | 293.4 (−291.7–878.6) | 1.31 (0.80–2.14) | 1.10 (0.66–1.83) | |
| Total | 140 639.0 | 186 | 132.3 (113.2–151.3) |
†
Adjusted for cohort (JPHC Study I, JPHC Study II, Three‐Prefecture Cohort Study or JACC Study).
‡
Adjusted for cohort and number of cigarettes smoked per day (0–19, 20–39, 40–59, ≥60 or unknown). CI, confidence interval.