Anticipating Changes That May Affect Intervention Fidelity

Monitoring Intervention Fidelity and Adaptations

Section 2

Anticipating Changes That May Affect Intervention Fidelity


Leah Tuzzio, MPH

Eric Larson, MD, MPH

James Fraser

Russell Glasgow, PhD

Michael Ho, MD, PhD


Contributing Editor

Liz Wing, MA

“External changes can give rise to unexpected challenges for the trials, including decisions regarding how to respond to new clinical practice guidelines, increased difficulty in implementing trial interventions, achieving separation between treatment groups, and differential responses across sites.” (Curtis et al. 2019)

As described in the Assessing Feasibility chapter, it is important for study teams to pilot their ePCT intervention and assess feasibility with the partner health system as much as possible before launching the implementation phase. Piloting provides the real-world feedback needed to understand the capabilities, capacities, and workflows of sites delivering the intervention.

During the study’s implementation phase, a variety of changes within clinics, hospitals, and health systems may have an impact on the delivery of the embedded intervention. Researchers should expect changes to occur. One example could be when a component of the intervention is incorporated into usual care at a control site or cluster. This could be due to unintentional spill-over of intervention effects; healthcare system initiatives, guidelines, or policies that focus on solving a similar problem; or changes in staffing, clinic workflow, or leadership. In the early stages of intervention implementation, it will be beneficial to identify and monitor aspects that may be vulnerable to internal and external changes and that could drive adaptations. Also important is knowing in advance which features of the embedded intervention are so essential to its effectiveness that modifying them could negatively affect the study’s outcomes and impact.

Examples of Changes That Can Drive Adaptations

Location of Change Examples
Within a clinical setting
  • Competing clinical initiatives
  • Workflow complexities
  • Maintaining expertise amid clinical staff turnover or reduction
  • Resource and tool constraints
  • Abandonment of intervention tasks
  • Intervention design is overly complicated or burdensome
  • Discovering new efficiencies
Across a health system
  • Quality improvement initiatives
  • Leadership buy-in
  • Leadership, clinician, and staff turnover
  • Champion or facilitator turnover
  • EHR system updates, transitions, or other technology/tools changes
  • Data collection processes
  • Data quality and pertinence to process and outcomes
  • Changes to health system priorities, incentives, or ownership
  • Clinical guideline changes
At the community level
  • Competition
  • Emerging community priorities
  • Social media trending topics (eg, vaccinations)
At the state or national level
  • Healthcare system market consolidation
  • Policy changes
  • Payment coverage changes, especially Medicare and Medicaid
  • Regulatory changes




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Curtis LH, Dember LM, Vazquez MA, et al. 2019. Addressing guideline and policy changes during pragmatic clinical trials. Clin Trials. 16:431-437. doi:10.1177/1740774519845682. PMID: 31084378.

Version History

Published March 2020


Monitoring Intervention Fidelity and Adaptations: Anticipating Changes That May Affect Intervention Fidelity. In: Rethinking Clinical Trials: A Living Textbook of Pragmatic Clinical Trials. Bethesda, MD: NIH Health Care Systems Research Collaboratory. Available at: Updated March 27, 2020.