Visitors to the PhenX Toolkit site can browse by research domain or search using keywords. PhenX Toolkit users can select measures and save them in a cart. Users can easily add to or remove measures from their cart as they decide which PhenX measures would be most helpful for their study. The PhenX Toolkit provides a brief description of each measure, its purpose and rationale for inclusion, standardized protocols for collecting data on the measure, supporting information, and references. The PhenX Toolkit describes the requirements for each measure, including details about the personnel and equipment needed to collect data on the measures. Users can request a report that provides the details of their selections, thus facilitating incorporation of these measures into the study design. In addition, the Toolkit alerts users if additional measures (essential data) are needed to interpret a selected measure. For example, if Toolkit users select “blood pressure,” the users are prompted to also add “current age,” “gender,” “race,” and “ethnicity” to their cart (i.e., a specific collection of measures). After following a simple registration process, registered Toolkit
