JMIR Publications

ABSTRACT

Background:

Improving the cost-effectiveness and scalability of mental health interventions remains challenging. The Multiphase Optimization Strategy (MOST) framework provides a structured aproach for developing, optimizing, and evaluating behavioral interventions by balancing effectiveness with efficiency, economy, and scalability. It does so across three phases: Preparation (theoretical grounding and component selection), Optimization (experimental testing), and Evaluation (confirmatory trial). Digital mental health interventions are especially suited to this modular approach, as they enable researchers to easily manipulate components and personalize delivery.

Objective:

To examine how the MOST framework has been applied in the digital mental health field and to provide recommendations for future application.

Methods:

Systematic searches were conducted in Embase, CINAHL, Web of Science, PsycInfo, and PubMed. Papers were included if they used MOST to develop or optimize a digitally delivered mental health intervention. Studies targeting children under 12, reviews, and theoretical or simulated applications were excluded.

Results:

Twenty-nine papers representing 17 research projects met the inclusion criteria. The preparation phase was often incomplete - fewer than half of the studies reported a conceptual model, and optimization criteria and pilot testing were inconsistently reported. Seven projects completed at least one optimization trial, typically employing factorial designs, but progression to intervention refinement or evaluation was limited. Projects conducting multiple optimization rounds were more likely to achieve an optimized intervention.

Conclusions:

MOST is increasingly applied in digital mental health research but often only partially implemented. While factorial designs are widely adopted, critical preparatory elements are frequently missing. To fully realize MOST’s potential, future research should emphasize comprehensive application across all phases, iterative refinement and transparent reporting. Clinical Trial: -