Treatment adherence and App engagement
ADHD
SAID
Though no effect on adherence was observed, it is important to highlight that all groups exhibited an MPR above 100% in our study. These values are much higher than the established cutoff value used to classify participants as adherent and non-adherent in previous studies [Regarding the FOCUS ADHD App, we observed a high adoption rate, especially by those receiving a reinforcement for using the App (100% for the App + Discount vs. 75% for the App Group). User engagement has proved to be a key element in determining the effectiveness of digital interventions [Related to the complexities of using MPR as a measure of adherence, it is interesting to consider that our participants’ engagement with the App and their registration of medication intake could be considered a reasonable measure of adherence. The naturalistic nature of the present study prevented us from documenting that these registrations were associated with actual medication intake. That said, the fact that our participants made an effort to get onto the App and registered an intake and confirmed to our research assistants (via weekly contacts) that these registrations were associated with actual medication intakes, provides reasonable evidence that they took the medication. This suggests initial evidence that a financial incentive paired with the FOCUS ADHD App increased medication adherence, at least initially.In terms of retention of App use, no participant continued to register medication intake more than 80% of the time during the entire study in the App Group, while four participants in the App + Discount Group (16.7%) fulfilled this criterion. Though these numbers are low, they are consistent with the available mHealth literature [When evaluating ADHD knowledge assessment, no significant differences emerged among groups. However, the average baseline scores for the three groups were already above the adopted cutoff for indicating a good understanding of ADHD, which may have created a ceiling effect where only a small improvement could be observed in all groups. Creating a more interactive educational experience by customizing the available psychoeducational contents with specific patient characteristics or needs could improve the FOCUS ADHD App.When we analyzed the FOCUS ADHD App performance based on the uMARS questionnaire, the total average score of the evaluations from both groups of App users was above 3, a cutoff that has been utilized in previous studies as evidence of a positive evaluation of App quality [The literature also highlights the importance of designing and implementing personalized approaches to promote users’ engagement with digital mental health solutions [As clinical trials using digital technology continue, it will be important to consider the conditions for optimal implementation in clinical practice [There are some limitations to consider when evaluating the present results. The sample size was relatively small, and the protocol did not have a digital control group. There were income differences among study groups that were non-significant probably due to the large amount of variability within groups. Although this difference was not statistically significant, income could affect the salience of financial incentives.The current findings demonstrated that the FOCUS ADHD App obtained a high adoption rate and received positive evaluations from its users. In the present study, the use of the App did not increase treatment adherence as measured by MPR. That said, for those using the App, evidence of increased medication intake registrations in the group that received a discount on their medication offers initial evidence supporting the utility of combining financial incentives with mHealth solutions to increase treatment adherence. These data, together with prior evidence showing that App use can increase treatment adherence [