Effect of Cultural Adaptation of a Smartphone-Based Self-Help Programme on Its Acceptability and Efficacy: Randomized Controlled Trial.

Drop-out rates were high in both conditions, and no group difference was found regarding the acceptance of the intervention. The high drop-out rate stands in contrast with other trials testing Step-by-Step. Future research should examine cultural factors impacting recruitment strategies, as insights could help to reduce participant drop-out rates in clinical trials.