Table 4

 Odds ratios and confidence intervals for the interaction between time and statistically significant (p<0.05) predictors on helmet use (1 = yes; 0 = no) in 2001 and 2002*

PredictorEstimatep Value
*Models contain both main effects and interaction terms, though only results for interaction term are displayed.
Gender* time
    (Male-pretest)0.090.06
Proportion of days skied/snowboarded since 1 November
    (4th quartile-pretest)0.100.10
    (3rd quartile-pretest)0.060.43
    (2nd quartile-pretest)−0.140.12
Self reported ability
    (Intermediate-pretest)0.140.14
    (Expert-pretest)0.150.11
Type of equipment* time
    (Snowboard-pretest)0.040.34
Ski area characteristics:
Ski area region
    (Southwest–pretest)−0.030.77
    (Northwest-pretest)−0.020.72
    (California-pretest)0.080.29