ESTIMATING THE PREVALENCE AND FREQUENCY OF ADOLESCENT DRUG USE: DO THE MODELS FIT THE MEASURES?

We critically review recent studies to examine the measurement schemes and empirical models used to examine adolescent drug use, with a particular eye toward determining whether differences between the prevalence and frequency of use have been addressed. Several theoretical models suggest that there are differences but we find relatively few studies that have considered prevalence versus frequency, even though selection effects that dictate these processes affect conclusions about predictors of drug use. Using data from the 2004 U.S. National Survey of Drug Use and Health (NSDUH), (n=16,235), we provide an empirical example of why distinguishing prevalence and frequency of use is important. In particular, gender, age, and parent-child arguments are associated with the prevalence, but are not associated with the frequency of drug use. The associations between grades, religiousness, positive parental relations and drug use are overestimated substantially absent controls for the selection process inherent in the shift from any use to frequency of use. We therefore contend that adolescent drug use studies require greater attention to this selection process.