Table 1.

Distribution of cases and controls by sex, age at first sample, year of first sample, duration of follow-up, attained age, and smoking status

Cases (N = 1,741), n (%)Controls (N = 1741), n (%)
Sex*
    Men1,322 (75.9)1,322
    Women419 (24.1)419
Age at first sample (y)*
    <45980 (56.3)1,019 (58.5)
    45-54617 (35.4)599 (34.4)
    55-6444 (2.6)22 (1.3)
    ≥65100 (5.7)101 (5.8)
Year of first sample*
    1970-1975779 (44.8)835 (48.0)
    1976-1980292 (16.8)319 (18.3)
    1981-198595 (5.5)69 (4.0)
    1986-1990535 (30.7)476 (27.3)
    1991-199540 (2.2)42 (2.4)
Duration of follow-up (y)*
    1-5191 (11.0)185 (10.6)
    5-9391 (22.5)356 (20.4)
    10-14376 (21.6)351 (20.2)
    15-19317 (18.2)342 (19.6)
    20-24358 (20.6)393 (22.6)
    25-29108 (6.2)114 (6.6)
Attained age (y)
    <4564 (3.7)64 (3.7)
    45-54551 (31.6)564 (32.4)
    55-64557 (32.0)550 (31.6)
    ≥65569 (32.7)563 (32.3)
Smoking status
    Never smoker53 (3.0)445 (25.6)
    Ex smoker128 (7.4)411 (23.6)
    Current smoker1,393 (80.0)727 (41.8)
    Ever smoker96 (5.5)67 (3.8)
    Missing71 (4.1)91 (5.2)
  • * The distributions of cases and controls are similar as result of individual matching.

  • Pdifference between cases and controls (χ2 square test) < 0.0001.

  • Current or ex smoker (only information on ever/never smoking status was available in a subset of study subjects).