Table 1.

Baseline characteristics of the study sample of 49,343 conscripts born in 1949 to 1951 and ages 18–21 at conscription by exposure status

Among “ever” cannabis usersb
Study covariatesTotalNever drug use“Ever” use of cannabisPaUse more than 50 timesPaCannabis as “most frequently used drug”PaUnclear/missing/use of other drugsc
Total, n (%)d49,343 (100)40,271 (81.6)5,326 (10.8)879 (1.8)4,323 (8.8)3,746 (7.6)
Birth year<0.001<0.001<0.001
 19492,833 (100)2,122 (74.9)336 (11.9)73 (2.6)265 (9.4)375 (13.2)
 19508,826 (100)6,741 (76.4)1,161 (13.1)194 (2.2)952 (10.7)924 (10.5)
 195137,684 (100)31,408 (83.3)3,829 (10.2)612 (1.6)3,106 (8.2)2,447 (6.5)
Cryptorchidism0.8640.5280.805
 No49,085 (100)40,059 (81.6)5,297 (10.8)873 (1.8)4,299 (8.8)3,729 (7.6)
 Yes258 (100)212 (82.2)29 (11.2)6 (2.3)24 (9.3)17 (6.6)
Paternal testicular cancer0.1390.0010.476
 No49,267 (100)40,214 (81.6)5,314 (10.8)874 (1.8)4,315 (8.8)3,739 (7.6)
 Yes76 (100)57 (75.0)12 (15.8)5 (6.6)8 (10.5)7 (9.2)
Tobacco smoking<0.001e<0.001e<0.001e
 Never20,906 (100)18,273 (87.4)790 (3.8)75 (0.4)628 (3.0)1,843 (8.8)
 1–5 cigarettes/day5,428 (100)4,557 (83.9)477 (8.8)57 (1.1)396 (7.3)394 (7.3)
 6–10 cigarettes/day10,058 (100)8,114 (80.7)1,294 (12.9)194 (1.9)1,059 (10.5)650 (6.4)
 11–20 cigarettes/day11,198 (100)8,229 (73.5)2,268 (20.2)405 (3.6)1,861 (16.6)701 (6.3)
 More than 20 cigarettes/day1,747 (100)1,098 (62.8)497 (28.5)148 (8.5)379 (21.7)152 (8.7)
 Missing6 (100)00006 (100)
Alcohol consumption (g of 100% alcohol/week)<0.001e<0.001e<0.001e
 Abstainers (0 g)2,957 (100)2,738 (92.6)44 (1.5)20 (0.7)35 (1.2)175 (5.9)
 Light (1–100 g)36,253 (100)31,134 (85.9)2,761 (7.6)395 (1.1)2,217 (6.1)2,358 (6.5)
 Moderate (101–250 g)7,904 (100)5,475 (69.3)1,883 (23.8)277 (3.5)1,564 (19.8)546 (6.9)
 Heavy (>250 g)1,454 (100)730 (50.2)594 (40.8)176 (12.1)470 (32.32)130 (8.9)
 Missing775 (100)194 (25.0)44 (5.7)11 (1.4)37 (4.8)537 (69.3)
  • aP values for trend in comparison with “Never drug use.”

  • bPercentages for “Use more than 50 times” and “Cannabis as most frequently used drug” are calculated out of total (100%).

  • cExposure to any drug use ever, but not to cannabis or missing/unclear information on drug use.

  • dCategories “Never drug use,” “Ever use of cannabis,” and “Unclear/missing/use of other drugs” sum up to 100%.

  • eP value calculated for categories with nonmissing observations.