Use of a motivational interviewing-informed strategy in group orientations to improve retention and intervention attendance in a randomized controlled trial.

High retention and treatment adherence are essential to ensure the quality of evidence from clinical trials. Strategies for improving these have been explored but actual rates in lifestyle intervention trials indicate challenges. This study examined the use of a motivational interviewing-informed strategy during interactive group orientations prior to obtaining informed consent, collecting baseline data and randomization in a healthy dietary pattern intervention trial for asthma control in adults. The themes generated from small group discussions and echoed in large group discussions during the orientation sessions helped potential participants better understand the scientific rationale of the research design and procedures and the practical implications for them to participate in the study. Potential participants reported significantly lower confidence of completing the study after the group orientation. This suggests that the group orientations helped potential participants identify challenges to completing the study, have more realistic expectations about participation and be prepared if enrolled. Both retention (92% of 90 participants at 6 months) and intervention attendance (99% of 46 intervention participants attended 80% of 11 weekly group/individual sessions) were high, suggesting the motivation interviewing-informed group orientation strategy may help improve retention and adherence in clinical trials.