When patients, clinicians, or other healthcare stakeholders raise a question that doesn’t already have an evidence-based answer, sometimes new research is needed to answer it. But in other cases, a careful look at results from research studies already completed can more quickly provide findings that patients and those who care for them can use to make informed choices. PCORI's Evidence Synthesis Initiative takes that approach.

Systematic Reviews

The most common type of evidence synthesis is the systematic review, which features a set of clearly specified, rigorous, reproducible, and transparent methods.

Rapid Reviews

A rapid review is an approach that accelerates and streamlines evidence synthesis methods to meet requirements of end users, producing rigorous and transparent evidence for decision making in a resource-efficient manner.

Topic Briefs

Topic Briefs identify and categorize the existing effectiveness and comparative effectiveness literature on a medical issue.

PCORI Health Care Horizon Scanning System

The Health Care Horizon Scanning System provides a systematic process to identify healthcare interventions that have high potential to alter the current standard of care.

Emerging Technologies and Therapeutics Reports

The reports offer summaries of evidence supporting new drugs, devices, and other healthcare technologies that are in use or may be available soon in the United States.


A meta-analysis typically summarizes the average treatment effect for the entire study population using statistical methods.

Other Secondary Data Reuse Opportunities

There are other approaches that can be helpful in studies with a diverse group of people and a wide range in individual responses to an intervention.

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Posted: October 27, 2017; Updated: December 23, 2019

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