Purpose

To evaluate, using a randomized trial, whether a web-based self-administered questionnaire (web SAQ) can improve the reporting rate of substance use in adolescents compared with a paper-and-pencil self-administered questionnaire (paper SAQ).

Methods

Students of junior high, senior high, and vocational high schools in Taipei City and County were selected by a stratified, two-stage, probability proportional to size, random sampling. For each class selected, half of the students were randomly assigned to paper SAQ (n = 990) and the other half to web SAQ (n = 928). The inverse of the sampling probability for each individual was then used as sampling weight in the estimation of prevalence and logistic regression analysis.

Results

For readily available substances, the lifetime prevalence in the web SAQ group was significantly higher for alcohol use and borderline higher for tobacco and betel nut use compared to those of the paper SAQ group. For illicit drug use, the lifetime prevalence for the web SAQ group was significantly higher for the use of amphetamines, and borderline higher for ketamine. In multiple logistic regression analysis, the differences between the two groups in the use of alcohol, tobacco, and amphetamines remained significant. Boys, as well as both junior-high and vocational high school students who responded using the web SAQ, were more likely to report alcohol or tobacco use than those using the paper SAQ.

Conclusions

Web SAQ leads to higher reporting rates of commonly used substances in adolescents compared with those of paper SAQ.