Intervention delivery for embedded pragmatic clinical trials: Development of a tool to measure complexity

Contemp Clin Trials. 2023 Mar:126:107105. doi: 10.1016/j.cct.2023.107105. Epub 2023 Jan 26.


Background: Conducting an embedded pragmatic clinical trial in the workflow of a healthcare system is a complex endeavor. The complexity of the intervention delivery can have implications for study planning, ability to maintain fidelity to the intervention during the trial, and/or ability to detect meaningful differences in outcomes.

Methods: We conducted a literature review, developed a tool, and conducted two rounds of phone calls with NIH Pragmatic Trials Collaboratory Demonstration Project principal investigators to develop the Intervention Delivery Complexity Tool. After refining the tool, we piloted it with Collaboratory demonstration projects and developed an online version of the tool using the R Shiny application (

Results: The 6-item tool consists of internal and external factors. Internal factors pertain to the intervention itself and include workflow, training, and the number of intervention components. External factors are related to intervention delivery at the system level including differences in healthcare systems, the dependency on setting for implementation, and the number of steps between the intervention and the outcome.

Conclusion: The Intervention Delivery Complexity Tool was developed as a standard way to overcome communication challenges of intervention delivery within an embedded pragmatic trial. This version of the tool is most likely to be useful to the trial team and its health system partners during trial planning and conduct. We expect further evolution of the tool as more pragmatic trials are conducted and feedback is received on its performance outside of the NIH Pragmatic Trials Collaboratory.

Keywords: Clinical workflow; Complex interventions; Implementation.

Publication types

  • Review
  • Research Support, N.I.H., Extramural

MeSH terms

  • Communication
  • Delivery of Health Care*
  • Humans
  • Research Design*