Project Summary

One of PCORI’s goals is to improve the methods that researchers use for patient-centered outcomes research. PCORI funds methods projects like this one to better understand and advance the use of research methods that improve the strength and quality of comparative effectiveness research.

What is the project about?

Clinical trials test how well new treatments or programs work for a specific group of people, such as people with diabetes. But people who take part in a clinical trial may not represent everyone from that group. For example, people in the trial may be healthier than people who aren’t in the trial. To address this issue, researchers have developed statistical methods that apply results from one or more clinical trials to the larger group of interest. But these methods don’t work well when data are missing. Data may be missing:

  • Within a trial, for example, when patients stop taking part in the trial
  • When researchers have not collected data about patient traits from patients in the trial

In this study, the research team is developing methods to apply results from clinical trials with missing data to the larger group of interest.

How can this project help improve research methods?

Results may help researchers apply results from clinical trials to the larger group of interest.

What is the research team doing?

First, the research team is creating new methods for applying the results of clinical trials with missing data to the larger group of interest. Next, the team is testing the new methods on data that mimic real patient data. Finally, the team is applying the methods to six trials of programs for youth at risk for HIV.

Research methods at a glance

Design ElementDescription
GoalTo create and test methods to transport or generalize results from clinical trials to the target population
  • Develop identifiability conditions
  • Develop methods for transporting results from clinical trials to target population
  • Conduct simulation analysis and empirical analysis for performance evaluation of methods

*Methods to Support Innovative Research on AI and Large Language Models Supplement
This study received supplemental funding to build on existing PCORI-funded comparative clinical effectiveness research (CER) methods studies to improve understanding of emerging innovations in large language models (LLMs).

Project Information

Jon Steingrimsson, PhD
David Barker, PhD
Brown University
Missing Data When Transporting Treatment Effects from Clinical Trials to a Target Population

Key Dates

June 2020
May 2025


Award Type
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: April 23, 2024