Table 5.

Marijuana smoking and the risk of HNC by tobacco and alcohol status

Never tobacco users*,
Never alcohol users
CasesControlsOR (95% CI)CasesControlsOR (95% CI)
Total3531,017345997
Marijuana smoking
    Never2957971.00 (reference)3119151.00 (reference)
    Ever572200.93 (0.63-1.37)34791.27 (0.77-2.12)
    Missing1003
    P for heterogeneity0.210.06
Frequency of marijuana smoking (times per day)
    Never2957971.00 (reference)3119151.00 (reference)
    0-1522050.93 (0.62-1.39)26681.30 (0.74-2.28)
    >15150.92 (0.31-2.68)8111.18 (0.43-3.19)
    Missing1003
    P for trend0.720.42
    P for heterogeneity0.060.22
Duration of marijuana smoking (in years)
    Never2957971.00 (reference)3119151.00 (reference)
    >0-5311130.99 (0.62-1.57)12450.86 (0.42-1.77)
    >5-109470.69 (0.32-1.51)6111.22 (0.41-3.61)
    >10-206350.60 (0.24-1.50)6131.38 (0.47-4.04)
    >2011251.60 (0.73-3.52)10103.12 (1.17-8.36)
    Missing1003
    P for trend0.990.05
    P for heterogeneity0.530.18
Cumulative exposure (joint-year)
    Never2957971.00 (reference)3119151.00 (reference)
    >0-2411760.87 (0.57-1.33)16590.99 (0.52-1.88)
    >2-55180.89 (0.31-2.53)3100.58 (0.15-2.26)
    >511261.34 (0.62-2.92)15103.25 (1.31-8.02)
    Missing1003
    P for trend0.800.07
    P for heterogeneity0.170.23
  • * OR adjusted for age (categorical), sex, race, study, education level, and alcohol duration (continuous). Does not include Tampa and Latin America studies.

  • Never tobacco users are never users of cigarette, pipe, cigar, chew, and snuff. Does not include Tampa and Latin America studies.

  • OR adjusted for age (categorical), sex, race, study, education level, pack-year (continuous), duration of smoking pipe (continuous), and duration of smoking cigar (continuous). Does not include Seattle and Latin America studies.