What are the T0 to T4 Research Classifications?

In June 2013, the Institute of Medicine (IOM) released an independent appraisal of the Clinical and Translational Science Award (CTSA) program that supplies major funding for ICTR and more than 60 other CTSA sites nationwide. Widely considered favorable to the CTSA program, the report nevertheless contained a number of recommendations to further strengthen the consortium, including one to change research classification definitions.

T0 to T4 definitions

The T0 to T4 classification system is a way to describe where research sits on the translational science spectrum. Translation is broadly defined as:

The process of turning observations in the laboratory, clinic and community into interventions that improve the health of individuals and the public — from diagnostics and therapeutics to medical procedures and behavioral changes – National Center for Advancing Translational Sciences

In response to the report, ICTR and many other CTSA sites adopted the IOM recommended T0 to T4 research classification to better track our research portfolio along the entire research continuum from basic discovery research to changes in community health. While the system culminates in public health (T4), ideally, patients and stakeholder are involved during all translational stages.

T0 Research: basic biomedical research, including preclinical and animal studies, not including interventions with human subjects;
T1 Research: translation to humans, including proof of concept studies, Phase 1 clinical trials, and focus on new methods of diagnosis, treatment, and prevention in highly-controlled settings;
T2 Research: translation to patients, including Phase 2 and 3 clinical trials, and controlled studies leading to clinical application and evidence-based guidelines;
T3 Research: translation to practice, including comparative effectiveness research, post-marketing studies, clinical outcomes research, as well as health services, and dissemination & implementation research; and
T4 Research: translation to communities, including population level outcomes research, monitoring of morbidity, mortality, benefits, and risks, and impacts of policy and change.

ICTR Pilot Awards Reflect the T0 to T4 Classification System

The T0 to T4 classification system replaced the Type 1 Translational Research (T1TR) and Type 2 Translational Research (T2TR) categories to allow more precise identification of supported research and development of a diverse, balanced research portfolio.