Is Inclusion of a Dummy Drug Necessary for Estimating Perceived Prevalence of Substance Use by Classmates?

Background: Substance abuse among students is a worldwide concern. As a widely applied method, nominative technique is employed to estimate the prevalence of a specific behavior among a population by questioning informed people. Objectives: The current study aimed at examining the necessity of including a dummy drug (i.e., relevin) in the list of drugs that are requested via nominative technique. Patients and Methods: Totally, 12 schools were selected using a stratified cluster sampling method in Kerman city, Southeastern Iran, and all their grade 10 students were recruited in the current study. A well-validated questionnaire was also used to ask students about the frequency of using six substances among their classmates, in addition to the items associated with risk-taking tendency and self-report substance use by themselves. To analyze the data chi-square, Cramer’s V, multiple logistic regression tests was used. Results: The mean age of the students recruited in the current study was 16.2 ± 0.6 years (n = 830) and approximately 53% of them were female. The consumption of relevin by classmates was reported higher in females (10.2%) than males (6.1%), in urban areas (10.6%) than rural ones (4.0%), and in subjects with a higher tendency toward substance abuse (17.6%) (P < 0.05). The belief in the use of relevin by classmates was not correlated with perceived use of any drugs by classmates. Frequency of self-reported substance use in subjects choosing the use of relevin by classmates was also comparable to those who did not declare the use of relevin by classmates. Conclusions: It was concluded that there might be no need for the inclusion of a dummy drug as an indicator of reliability to the list of substances that are being asked of students in the nominative technique.