Perceived behavioral control was measured by 3
items indicating students’ judgment of their ability to
control drug use. Examples include ‘‘It’s difficult for
me to avoid using drugs,’’ ranging from strongly agree
(+1) to strongly disagree (+7); ‘‘I have confidence
that I will not use any drugs,’’ ranging from strongly
disagree (+1) to strongly agree (+7); and ‘‘Whether
to use drugs or not is up to me,’’ ranging from
strongly disagree (+1) to strongly agree (+7). A
higher score indicated greater control over not using
drugs.
We used intention not to use drugs as a proxy
measure for drug-free behavior. Intention not to use
drugs was measured by 3 items evaluating students’
intentions not to use drugs in the next month. Two
ranged from strongly disagree (+1) to strongly agree
(+7). The third item was scored from 1 to 10. ‘‘Given
ten occasions in which you have the chance to use
drugs, how many times would you expect not to use
them?’’ All 3 were converted to standardized scores for analysis (standardized T scores, Mean = 50, SD = 10).
Cronbach’s αs were .85 or greater for attitude (.90),
subjective norm (.85), PBC (.90), and intention not to
use drugs (.92).
Life skills were measured by 16 items based on
World Health Organization definitions.20 A question
for creative and critical thinking was ‘‘I can judge
the advantages and disadvantages of drug use by
their health and social consequences.’’ A question
for coping with stress and emotions was ‘‘When
feeling upset or bored, I won’t use any drug to
change my mood.’’ A question for communication
and interpersonal relationships was ‘‘I can effectively
refuse to use drugs when someone offers me drugs.’’
A question for self-awareness and empathy was ‘‘I
know what my reactions or behavior may be when
I am in a bad mood (ex. depressed or irritable).’’
A question for decision-making and problem-solving
was ‘‘Before deciding whether to use drugs or not, I
can think over the possible consequences.’’ Students
reported the possibility of performing the skill over
a range of never (+1) to always (+7). Cronbach’s
α for the life skills scale was .93. Factor analysis of
each variable indicated that a single factor on each
scale accounted for 49.88% to 90.50% of the variance
(Table 2).