TABLE 4

Crude and Adjusted Relative Risks for Smoking Initiation During the Observation Period

VariableRelative Risk
Crude95% Confidence IntervalAdjusteda95% Confidence Interval
Cigarette-advertisement exposure
    Tertile 1 (low) (reference)
    Tertile 2 (medium)1.300.90–1.880.930.63–1.36
    Tertile 3 (high)2.19d1.67–2.861.46b1.08–1.97
Other advertisement exposure
    Tertile 1 (low) (reference)
    Tertile 2 (medium)1.240.93–1.670.990.72–1.34
    Tertile 3 (high)1.39b1.04–1.850.980.71–1.34
Age, y
    10–11 (reference)
    121.86c1.25–2.771.57b1.05–2.35
    132.74d1.84–4.101.77c1.17–2.68
    14–173.10d1.96–4.901.89c1.18–3.02
Gender
    Girls (reference)
    Boys1.38c1.09–1.761.180.92–1.51
SES
    Quartile 1 (lowest) (reference)
    Quartile 20.760.56–1.030.790.58–1.09
    Quartile 30.55c0.37–0.810.64b0.44–0.95
    Quartile 4 (highest)0.35d0.20–0.600.43c0.25–0.74
State
    Schleswig-Holstein (reference)
    Hamburg1.020.53–1.940.820.55–1.22
    Brandenburg1.240.72–2.151.210.86–1.69
Having a parent who smokes
    No (reference)
    Yes1.39b1.08–1.781.130.87–1.46
Having friends who smoke
    No (reference)
    Yes3.25d2.51–4.202.24d1.69–2.96
Sensation-seeking
    Below median (reference)
    Above median2.26d1.79–2.871.66d1.29–2.15
School performance
    Excellent (reference)
    Good1.410.89–2.231.310.81–2.13
    Average/poor2.49d1.57–3.931.83b1.12–2.97
Television screen time (continuous variable)1.090.99–1.200.940.86–1.03
Median incidence rate ratio
    School1.19
    Class1.00
  • a Adjusted for all of the variables listed.

  • b P < .05.

  • c P < .01.

  • d P < .001.