Table 2

Rates of multiple (3+) sexual partners in late adolescence according to substance use and associated ORs (unadjusted for other substance use) in each cohort, by gender

1987/1990 (‘earlier’) cohort1999/2003 (‘later’) cohortp Value of interaction by cohort
<3 Sexual partners3+ Sexual partnersOR (95% CI)*3+ Sexual partners3+ Sexual partnersOR (95% CI)*
 Current smoking
  Yes5422.08549.43.43 (2.21 to 5.32)4622.211245.52.61 (1.71 to 3.97)
 Excessive drinking
  Yes4819.58448.84.79 (3.00 to 7.64)5024.012450.43.42 (2.25 to 5.20)
 Ever used illicit drugs
  Yes7229.311164.54.38 (2.85 to 6.73)11254.118776.02.71 (1.80 to 4.09)
 Current smoking
  Yes13731.92255.02.61 (1.34 to 5.06)4618.510450.04.29 (2.79 to 6.58)
 Excessive drinking
  Yes399.11025.03.54 (1.57 to 7.98)4016.18138.93.55 (2.27 to 5.56)
 Ever used illicit drugs
  Yes8620.01948.73.76 (1.92 to 7.37)7731.015574.96.72 (4.41 to 10.26)
  • p Values of interactions by gender: within earlier cohort—current smoking by gender, p=0.465, excessive drinking by gender, p=0.742, ever illicit drugs by gender, p=0.795; within later cohort—current smoking by gender, p=0.145, excessive drinking by gender, p=0.841, ever illicit drugs by gender, p=0.003.

  • * Adjusted for social class and age.

  • Defined as ≥22 units in the past week for boys, ≥15 units for girls.