Design and conduct of intervention-based research among cancer survivors.

Intervention trials in cancer survivors play an important and growing role in complementing the wealth of knowledge obtained from observational studies about how lifestyle can improve clinical, physiologic, and psychological outcomes. As the number of intervention trials grows, attention to study design and reporting is essential to establishing a high-quality data pool from which to make evidence-based recommendations and guidelines. We highlight several key issues important to the design and interpretation of intervention trials in cancer survivors. Intervention dose and duration both matter in trials of cancer survivors, yet few trials have evaluated different intervention doses and few intervention trials with multiyear follow-up exist. Finally, there is a need for interventions both of longer duration and those that take a practical trials approach and reflect clinical practice to speed implementation within practice and improve outcomes for cancer survivors.