Designing Individually Tailored Preventive-Interventions and the Use of Clinical Judgment

Adaptive preventive interventions and treatments are a new and promising approach involving the individualized tailoring of the planned intervention to meet participants' needs. These types of treatments constitute an enhancement of the classical randomized control trial. In adaptive preventive interventions, treatment dosage and/or type of treatment is assigned according to prespecified rules, based on each participant's values on key characteristics, called dosage moderators. An adaptive intervention consists not only of the treatment itself, but the treatment inextricably coupled with the dosage moderators, measures of dosage moderators, dosage assignment rules, and implementation of dosage assignment rules. A properly conducted adaptive intervention has the potential to reduce negative effects, reduce waste, increase compliance, and enhance intervention potency. We discuss fundamental design principles aimed at maximizing the strength and replicability of adaptive interventions. These principles include: selecting appropriate dosage moderators; obtaining valid and reliable measurements of these variables; specifying dosage assignment rules that are objective, comprehensive, and based on an accurate model of the relationship among moderators, treatment dosage, and outcome; and optimally implementing these dosage rules. We also discuss the role of clinical staff judgment in adaptive interventions. It is noted that despite the differences between adaptive preventive interventions and fixed preventive interventions, the approach to conducting a scientific evaluation of adaptive interventions is essentially the same as the approach required for fixed preventive interventions. This work is supported by the National Institute on Drug Abuse grant P50 DA10075 to the Center for Prevention Methodology.