Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented, and the researchers made changes or provided responses. The comments and responses included the following:

  • The reviewers generally found the report to be comprehensive and mostly requested clarifications on the statistical methods used and about the text in the figures. The researchers added details to the text and to figure captions.
  • A reviewer questioned the need to demonstrate that treatment would reduce risk less for a low-risk group than for a high-risk group. The researchers responded that high-risk patients are often but not always more likely to benefit from treatment.  They strongly disagreed with the suggestion that they did not need any analysis to assess how absolute treatment effects vary in relation to initial risk. The researchers added a section to the introduction to discuss the concept of heterogeneity of treatment effects. They also  added that there are strong theoretical reasons and good empirical evidence that treatment effects are not necessarily proportional across levels of risk. Therefore, the researchers argued that risk-stratified analyses are necessary to evaluate harm-benefit trade-offs.
  • A reviewer argued that the study’s stratification of risk, a continuous measure, into discrete groups was arbitrary. Each stratum encompassed a great deal of heterogeneity of risk. They stated that patients with risk scores closer to the middle might be more like patients in the other stratum, rather than patients within their own stratum, but at the other end of the risk score continuum. The researchers responded that it is customary to categorize patients into subgroups when analyzing heterogeneity of treatment effects in clinical trials. The researchers agreed that dividing patients into discrete groups has some disadvantages, but even so, using risk strata can help illustrate the clinical importance of differences in treatment effects. In the report, the researchers acknowledged the lack of consensus on how to optimally group continuous measures and suggested that this is an area warranting future methodological research.

Conflict of Interest Disclosures

Project Information

David Kent, MD, MS
Tufts Medical Center, Inc.
Predictive Analytics Pilot Study: Assessment of Heterogeneity of Treatment Effects in Two Major Clinical Trials

Key Dates

April 2017
June 2019

Study Registration Information


Has Results
Award Type
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 4, 2022