Using the Multiphase Optimization Strategy (MOST) to Develop an Optimized Online STI Preventive Intervention Aimed at College Students: Description of Conceptual Model and Iterative Approach to Optimization

Abstract

This chapter describes some aspects of an application of the multiphase optimization strategy (MOST) to optimize and evaluate itMatters, an online intervention that targets the intersection of alcohol use and sexual behaviors to reduce sexually transmitted infections (STIs) among college students. The chapter emphasizes two aspects of this application. First, we describe the development of a detailed conceptual model during the preparation phase of MOST. This conceptual model guided decisions such as the choice of outcome variables. Second, we describe an iterative approach to experimentation during the optimization phase of MOST. The objective of the iterative approach is to build a highly effective intervention by using repeated optimization trials to evaluate which intervention components meet a given criterion for effectiveness and which do not. Revisions are undertaken to improve the components that do not meet the criterion, and then a subsequent optimization trial is used to reevaluate the components. This iterative approach has the potential to enable the investigator to develop more effective, efficient, economical, and scalable interventions.