Table 2

Age-specific associations of lung cancer mortality with duration and intensity among current smokers

Age group and genderIntensity βIk (RR: 95% CI)aDuration βDk (RR: 95% CI)bDeviance/dfc
40–49
 Men0.95 (2.6: 0.8–3.1)1.9 (6.7: 0.5–94)0.75
 Women0.96 (2.6: 1.3, 3.7)2.8 (16: 2.7, 95)1.27
50–59
 Men0.52 (1.7: 1.3–2.1)2.6 (13: 6.2–29)0.57
 Women0.75 (2.1: 1.6, 2.7)2.2 (9.4: 4.3, 21)0.81
60–69
 Men0.37 (1.4: 1.3–1.7)2.4 (11: 6.0–20)1.18
 Women0.78 (2.2: 1.8, 2.6)1.5 (4.7: 2.7, 8.1)1.09
70–79
 Men0.39 (1.5: 1.3–1.7)1.8 (6.0: 2.2–16)0.58
 Women0.95 (2.6: 2.0, 3.4)1.3 (3.5: 1.7, 7.2)1.04
  • a The intensity of smoking reflects the number of cigarettes smoked per day, as reported at baseline, and was modeled as the logarithm of intensity; analyses exclude nonsmokers and former smokers. β̂Ik is log of age-specific hazard ratio for log-intensity; RR is the hazard ratio, followed by associated 95% confidence intervals.

  • b Age and the duration of smoking increase with each year of follow-up, assuming that current smokers continue to smoke; duration was modeled as the logarithm of duration. β̂Dk is log of age-specific hazard ratio for log-duration; RR is the hazard ratio, followed by associated 95% confidence intervals.

  • c df, degrees of freedom.