[The prevalence of amphetamine use in adolescent students: self-reported and urine analysis]

The prevalence of amphetamine use was studied using an anonymous questionnaire given to 3548 adolescent students aged 12--15, with a response rate of 98.6%. This questionnaire was developed and evaluated by the authors. A complete set of data was collected on 3200 subjects, making up 90.2% of all students surveyed. Eighty-five (2.7%) students admitted that they had used amphetamines; that is, 64 of the 1,584 male (4.0%), and 21 of the 1,616 female (1.3%) respondents. The life-time prevalence odds ratio estimation was elevated in male (POR = 3.2, 95% CI 1.9--5.3), as compared to female students. The life-time prevalence rates increased with age only among male students (P trend = 0.01). Seven hundred and twenty four male students were randomly tested for the presence of amphetamines in their urine using thin layer chromatography and fluorescence polarization immunoassay. Of six students who tested positive, five asserted that they had not used amphetamines. The point prevalence rate of amphetamine use based on the urine tests was 0.9% among the 652 students who had completed questionnaires. This rate was higher than on self-reported use of amphetamines (rate difference 0.9%, 95% CI 0.2--1.6%). In this group, 27 (4.1%) admitted that they had used amphetamines. The estimated overall life-time prevalence rate was at least 4.9% (32/652), with 95% CI between 3.2% and 6.6%.