To address each PhenX research domain, a working group of domain experts is assembled. The working groups are composed of 6–9 domain experts from academic and government institutions. Working group members are carefully selected to include a balance of members with domain expertise and experience in epidemiology and genomics research. Each working group member commits to participating in the consensus process, which typically takes 7–9 months and includes 1 in-person meeting and 4–6 conference calls. The working group chairs play a key role, leading the working group throughout the consensus-based process. Working group participants are recognized on the project portal (https://www.phenx.org/). The working groups convene and use a consensus-based process to select 15 measures to be included in the PhenX Toolkit. Limiting the number of measures to 15 per domain ensures that the Toolkit includes only the highest-priority, well-established measures and also keeps the Toolkit a manageable size.
