Excessive substance use screening to encourage behaviour change among young people in primary care: Pilot study in preparation for a randomized trial

Introduction Alcohol, cannabis and other substance use affects young people's health. Primary care physicians are encouraged to screen and provide brief interventions for substance use in this population, but implementation is often limited. Pre-consultation self-administered screening may decrease at-risk substance use and could have population-level benefits. A randomized controlled trial is planned to test this hypothesis. The present pilot study's objective was to assess the feasibility of methods for the future trial. Methods The parallel-group randomized controlled pilot trial was undertaken in 6 primary care practices in Geneva, Switzerland, over 2 months. 29 patients aged 15–24 years consulting for any reason were randomly assigned to intervention (substance use screening, n = 14) or control (physical activity questionnaire, n = 15) using computer-generated random number tables. Outcomes were assessed one month later by telephone questionnaire. Physicians, practice staff and outcome assessors were blinded to allocation. The primary outcomes were feasibility of procedures and acceptability to participants, primary care physicians and practice staff. Results Of 16 participants reached at follow-up, 3 reported excessive substance use. Methods were acceptable to all participants, especially regarding confidentiality. Three participants were lost due to technical difficulties with the consent form. No major problems with study methods were reported in the practices. 4 practices did not meet recruitment targets. Conclusion The study procedures proved to be feasible in primary care practices and acceptable to young people who were readily available to participate. The main challenge for the future full-sized trial will be to ensure that recruitment targets can be met.