Substance use prevention program for adolescents with intellectual disabilities on special education schools: a cluster randomised control trial.

Background: Students without intellectual disability (ID) start experimenting with tobacco and alcohol between 12 and 15 years of age. However, data for 12- to 15-year old students with ID are unavailable. Prevention programs, like 'PREPARED ON TIME' (based on the attitude-social influence-efficacy model), are successful, but their efficacy has not been studied in students with ID. The objectives of this study were (1) to undertake a cluster randomised control trial to test the efficacy of the e-learning program among 12- to 15-year old students with mild and borderline ID in secondary special-needs schools and (2) to examine the tobacco and alcohol use for this population.

Methods: Five schools, randomly selected to be part of either the experimental group or the control group, participated in this study. Passive informed consent was used in which parents and their children can refuse to participate in the study, resulting in 111 students in the experimental group and 143 students in the control group. A total of 210 students completed both baseline and follow-up questionnaires. Primary outcome variables are the knowledge and attitude towards alcohol and tobacco use. This study is registered in the ISRCTN registry with number ISRCTN95279686.

Results: Baseline findings showed that a large proportion of all respondents had initiated smoking (49%) and drinking (75%), well above the expected numbers based on national figures. 'PREPARED ON TIME' did not affect the behavioural determinants (i.e. attitude, subjective norm and self-efficacy), except modelling on smoking. Additionally, alcohol-related knowledge of students in the experimental group increased after the completion of the program.

Conclusions: To obtain effective results on behavioural outcomes from 'PREPARED ON TIME', a greater degree of flexibility (i.e. repetition, extension of the program, role playing, etc.) is required. Furthermore, prevention needs to be implemented at a younger age, as 6% of the students tried their first cigarette and 15% of the students drank alcohol at the age of 10 years or younger.