Quantifying the effects of screening interventions using intermediate trial outcomes
Principal Investigator
Name
Dr. Edmund Njeru Njagi
Degrees
Ph.D.
Institution
University of Warwick
Position Title
Associate Professor
About this CDAS Project
Study
PLCO
(Learn more about this study)
Project ID
PLCO-1939
Initial CDAS Request Approval
Sep 9, 2025
Title
Quantifying the effects of screening interventions using intermediate trial outcomes
Summary
High quality randomised controlled trials (RCTs) are considered the most appropriate studies for establishing the benefits and harms associated with health screening. However RCTs of screening interventions require lengthy follow-up to generate reliable evidence on mortality and/or morbidity reductions, and hence the need for new methods to generate reliable results based on intermediate trial outcomes. This project aims to develop a conceptual and methodological framework for quantifying potential mortality and morbidity reductions of screening interventions based on intermediate trial outcomes. The work we have undertaken so far using simulated data has shown that our approach provides reliable estimates of mortality/morbidity reductions of screening in hypothetical trial settings. The PLCO data are requested to assess the performance of our methodological approach under ‘real-world’ trial conditions. The knowledge generated by this application will be used to produce much needed guidance on how best to quantify mortality/morbidity reductions of screening interventions when there is little RCT data as well as helping to understand when such estimates may or may not accurately approximate observed reductions.
Aims
The specific aims are,
(1) To compare the estimated mortality/morbidity reductions with trial observed reductions.
(2) To explore the factors associated with discordant findings
(3) To develop guidance on use of intermediate outcomes in screening evaluations
Collaborators
Professor Sian Taylor-Phillips (University of Warwick)
Professor Keith Abrams (University of Warwick)
Professor Bethany Shinkins (University of Warwick)