Principal Findings
depression, anxiety
The primary objective of this adaptive clinical trial was to evaluate the efficacy of various support intensities of a transdiagnostic biopsychosocial DMH intervention program, Life Flex, for anxiety or depression in adults. This study aimed to investigate the efficacy of an adaptive intervention design by testing whether therapist assistance (low and high intensity) in the form of video chat support produced significant clinical outcomes compared with a self-help DMH intervention program only. In the sample of 103 participants, we found no statistically significant difference between the participants who were stepped up to receive therapist assistance and those who remained in the DMH intervention program–only condition for outcomes of anxiety and depression. The participants in all 3 treatment conditions demonstrated significant improvement in anxiety and depression over the course of the intervention, with a large treatment effect size change. Quality of life (scores on the health-related quality-of-life utility index) improved across all 3 treatment conditions. This section highlights some of the benefits and challenges of adaptive intervention research designs, with implications for the stepped-care models discussed.As this trial used an adaptive intervention design, the results indicate that participants who continued in the Life Flex program–only condition did well. Regarding those participants who met the stepped-care criteria of the study, it could also be argued that they did well after having their treatment program augmented with therapist assistance. It could be speculated that, without the adaptive design, participants who did not engage with the program or those with moderate-to-high symptom severity may have dropped out completely from the Life Flex program–only condition.In step 1 of the adaptive trial, all eligible participants (n=113) were given access to the preintervention questionnaire. At week 3, a total of 64.6% (73/113) of the participants met the criteria to have their treatment program augmented with therapist assistance. For 58% (42/73) of these participants, the stepped-care rule of no program engagement was met, followed by 26% (19/73) who met the no-engagement and noncompletion of scheduled assessment rule, 7% (5/73) who met symptom severity criteria, and 10% (7/73) who met both the symptom severity and no-program-engagement criteria. These results are consistent with previous literature investigating engagement rates of self-help DMH interventions that have demonstrated high attrition and low completion rates in the absence of stepped care [The clinical trial presented an opportunity to capture low engagement early on, which meant that most participants allocated to low-intensity (29/36, 81%) and high-intensity (32/37, 86%) therapist assistance had the opportunity to access therapist assistance. This is important given the literature demonstrating the relationship between engagement and positive symptom outcomes in DMH intervention research [The large treatment effect size change found for the DMH intervention program–only condition in this study is consistent with an earlier single-group evaluation demonstrating the preliminary effectiveness of a fully automated self-help version of the Life Flex program [The finding of no significant difference among the 3 treatment conditions could also be explained by the nature of the clinical trial design. All participants underwent prescreening (semistructured phone interview and video chat diagnostic assessment), followed by postintervention and 3-month follow-up video chat diagnostic assessment interviews with provisional or generally registered psychologists. This contact with research personnel may have been therapeutic for participants. Previous research evaluating the timing and magnitude of symptom improvement found participants to improve following an initial assessment call, with authors concluding that even brief therapeutic contact can influence symptom outcomes in clinical trials [It is also important to consider the influence of participant self-selection bias [Closer examination of the available first treatment preferences of the participants who met the stepped-care criteria (63/73, 86%) indicates that 68% (43/63) preferred high-intensity therapist assistance, 17% (11/63) preferred low-intensity therapist assistance, and only 14% (9/63) preferred the Life Flex program only. The preferences of the participants who did not meet the stepped-care criteria were also examined. Of these participants, 45% (18/40) had a first treatment preference for high-intensity therapist assistance, 35% (14/40) had a preference for low-intensity therapist assistance, and 20% (8/40) had a preference for the Life Flex program only. The preference data across the entire sample indicate a strong preference among participants for therapist assistance (86/103, 83.5% first treatment preference for therapist assistance compared with 17/103, 16.5% preference for the Life Flex program only). This finding is similar to that of previous research [Despite preferences, participants who remained in the Life Flex program–only condition did just as well with regard to symptom reduction of primary outcomes (anxiety and depression) as participants who were stepped up to receive therapist assistance. The health-related quality-of-life utility index scores also indicated significant improvements in quality of life across all 3 treatment conditions. Given that there were no differences among the 3 conditions, the Life Flex program by itself could be the most accessible and cost-effective treatment option. The Life Flex program–only condition also had the highest percentage of program completion of the 3 treatment conditions at 72% compared with 57% for low-intensity therapist assistance and 60% for high-intensity therapist assistance. Therefore, it could also be speculated that participants may have relied on their video chat sessions with their therapist for delivery of program content, reducing engagement with the Life Flex program itself.Participants who were stepped up had their treatment program augmented with therapist assistance delivered via video chat technology. In both the low- and high-intensity therapist assistance conditions, participants received individualized guidance, with a key component of therapist assistance involving reinforcement and motivation enhancement. Therefore, it would be beneficial to further investigate self-efficacy and motivation as predictors of engagement and attrition (as is planned in a subsequent paper by the authors) to better understand who is most suited for self-help and who may benefit from therapist assistance within DMH adaptive intervention designs. Research designed to improve the implementation of stepped care through contextual behavioral science recommends that the “match-mismatch” design be applied to stepped-care research to enhance understanding of treatment intensity and dose based on participant-specific characteristics [