Statistical issues in pragmatic trials of behavioral economic interventions.

BACKGROUND: Randomized clinical trials provide gold-standard evidence for the efficacy of interventions, but have limitations, including highly selected populations that make inference on effectiveness difficult and a lack of ability to adapt and change midstream.

METHODS: We propose two innovations for pragmatic trial design.

RESULTS: Evidence-based evolutionary testing, a framework that allows adaptation of interventions and rapid-cycle innovation, preserves the power of randomization while acknowledging the need for adaptation and learning. An opt-out consent framework increases the fraction of the target population who participate in trials, but may lead to dampening of effect sizes.

CONCLUSION: Pragmatic trials offer numerous advantages in the evaluation of behavioral interventions in health. Statistical innovations, including evidence-based evolutionary testing and opt-out framing of consent and enrollment processes, can enhance the power of pragmatic trials and lead to more rapid progress.