Criteria for Selecting PhenX Protocols

The PhenX Steering Committee developed the criteria for selecting protocols for the PhenX Toolkit. These criteria include that protocols should be:

• Clearly defined
• Well established
• Use in major reference study (e.g., NHANES) or consortium (e.g., EMERGE)
• Already existing (i.e., WG members cannot create new protocols)
• Broadly validated and demonstrated utility
• Reproducible
• Reliable
• Low burden to participants and investigators

Whenever possible, protocols should also have/demonstrate:

• Cross-cutting relevance for population groups as well as diseases and conditions
• Prior use in omics research
• Open-source software and nonproprietary instruments preferred

Working Groups of experts recommend protocols for the Toolkit using these criteria and a consensus process that relies on community input. During deliberations, members present candidate protocols for consideration by the larger WG, including how well they adhere to the SC criteria.

These details are captured in specific Toolkit fields describing each protocol:

• Source — the original reference for the protocol (confirming it already exists), and often validity and reliability
• General References — additional evidence of validity and reliability and key studies that have used it
• Requirements — burden on participants and investigators
• Limited Availability — flag for proprietary protocols