Table 3.

Mortality rate ratios for death from lung cancer according to years since cessation of smoking among male current and ex‐smokers who started smoking at age 18–22 years (attained age, 40–89 years)

Status	Person‐years	No. lung cancer deaths	Mortality rate ratio † compared with current smokers (95% CI)
Never smokers	245 713.3	87	1.00
Current smokers	473 345.2	684	4.71 (3.76–5.89)
Ex‐smokers (years since cessation of smoking
0–4	58 730.7	91	3.99 (2.97–5.35)
5–9	51 366.0	50	2.55 (1.80–3.62)
10–14	40 776.2	29	1.87 (1.23–2.85)
15–19	24 576.1	12	1.21 (0.66–2.22)
20–24	16 750.7	6	0.76 (0.33–1.75)
≥25	18 746.1	9	0.67 (0.34–1.32)
Trend			P = 6 × 10−26 ‡

^† Adjusted for attained age (40–49, 50–59, 60–69, 70–79 or 80–89 years) and cohort (JPHC Study I, JPHC Study II, Three‐Prefecture Cohort Study or JACC Study).

^{‡ ‡} Trend for ex‐ and current smokers. CI, confidence interval.