About PhenX

PhenX (consensus measures for Phenotypes and eXposures)

The PhenX Toolkit (https://www.phenxtoolkit.org/) is an online catalog of standard measurement protocols for use in biomedical research. Established in 2007 with a cooperative agreement by the National Human Genome Research Institute (NHGRI) of the National Institutes of Health (NIH) and RTI International, the Toolkit is available at no cost to users.

PhenX protocols cover a broad scope of research domains (e.g., Demographics, Cardiovascular, Diet and Nutrition), while collections provide depth in specific areas (e.g., Substance Abuse and Addiction Research, Mental Health Research).

The PhenX Steering Committee (SC) supports and guides a consensus-based process with the scientific community to prioritize research domains and approve protocols for inclusion in the Toolkit. Liaisons from the NIH Institutes and Centers, and representatives from other government agencies, are invited to engage in the process.

Working Groups of scientists with relevant expertise areassembled to recommend measurement protocols for specific research domains. Expert Review Panels  review existing measures and protocols in the Toolkit and recommend updates to ensure that Toolkit content reflects current scientific standards.

The PhenX Toolkit

The PhenX Toolkit provides protocols that are well established and identified by experts in the field. The protocol page includes all the necessary information to administer the protocol and record the data, including:

  • A brief description of the protocol
  • The rationale for selecting the protocol
  • Details about personnel and equipment needed to collect the protocol
  • A description of special requirements for collecting the protocol
  • Variables
  • References
  • Tools to download the protocol and reports in several formats

PhenX Toolkit Features

  • Advanced search features enable you to use keywords and filters to quickly find what you need.
  • The dbGaP Variable Search identifies PhenX variables mapped to dbGaP variables and dbGaP variables mapped to PhenX variables.
  • Download Data Dictionaries, Data Collection Worksheets or REDCap Instrument ZIP files.
  • Link Your Study to find other studies using the same protocols and identify opportunities for cross-study analysis.
  • Registered users can Link Your Study, name and save multiple “My Toolkits” for different studies/protocols, share Toolkits with colleagues and collaborators, receive release notifications, and participate in outreach surveys.
  • Toolkit Guidance and Quick Start resources help new users become familiar with the Toolkit.


PhenX is funded by the National Institutes of Health (NIH) Genomic Resource Grant (U41HG007050) from the National Human Genome Research Institute (NHGRI) with current or prior funding support from the National Institute on Drug Abuse (NIDA), the Office of Behavioral and Social Sciences Research (OBSSR), the National Institute of Mental Health (NIMH), the National Heart, Lung, and Blood Institute (NHLBI), the National Institute on Minority Health and Health Disparities (NIMHD), and the Tobacco Regulatory Science Program (TRSP).


Dr. Carol M. Hamilton is the RTI International Principal Investigator, and Dr. Erin M. Ramos is the NHGRI Project Scientist.