Microrandomized trials: An experimental design for developing just-in-time adaptive interventions

Predrag Klasnja, Eric B. Hekler, Saul Shiffman, Audrey Boruvka, Daniel Almirall, Ambuj Tewari, Susan A. Murphy

Research output: Contribution to journalArticlepeer-review

336 Scopus citations


Objective: This article presents an experimental design, the microrandomized trial, developed to support optimization of just-in-time adaptive interventions (JITAIs). JITAIs are mHealth technologies that aim to deliver the right intervention components at the right times and locations to optimally support individuals' health behaviors. Microrandomized trials offer a way to optimize such interventions by enabling modeling of causal effects and time-varying effect moderation for individual intervention components within a JITAI. Method: The article describes the microrandomized trial design, enumerates research questions that this experimental design can help answer, and provides an overview of the data analyses that can be used to assess the causal effects of studied intervention components and investigate time-varying moderation of those effects. Results: Microrandomized trials enable causal modeling of proximal effects of the randomized intervention components and assessment of time-varying moderation of those effects. Conclusion: Microrandomized trials can help researchers understand whether their interventions are having intended effects, when and for whom they are effective, and what factors moderate the interventions' effects, enabling creation of more effective JITAIs.

Original languageEnglish (US)
Pages (from-to)1220-1228
Number of pages9
JournalHealth Psychology
StatePublished - 2015


  • Experimental designs
  • Intervention optimization
  • Microrandomized trials
  • mHealth

ASJC Scopus subject areas

  • Applied Psychology
  • Psychiatry and Mental health


Dive into the research topics of 'Microrandomized trials: An experimental design for developing just-in-time adaptive interventions'. Together they form a unique fingerprint.

Cite this