Findings
The V3+ Use Specification must contain a detailed description of the user groups, use environments, and the sDHT user interface. The user groups include end-users (individuals from whom data is captured) as well as carepartners, clinicians, researchers, and administrators. Characteristics of users (e.g., demographics, literacy, physical/cognitive capabilities, disease characteristics) and use environments (e.g., temperature, network availability, clutter) must be considered for risk management .

Recommendations
Developers must follow these four steps to create the Use Specification:
Identify all user groups: Create a list of users, including sub-categories (e.g., different types of researchers), and describe the characteristics of each group (e.g., health literacy, physical capabilities) to create detailed descriptions of representative users.
Identify all likely use environments: Create a list of typical environments (e.g., Home, Hospitals) and describe their characteristics (e.g., temperature, noise, network availability), also considering “edge cases” (e.g., extreme weather).
Describe the sDHT user interface: Detail all aspects of the hardware and software (visual, auditory, tactile cues), accessories (e.g., packaging, chargers), and all written materials and training (e.g., instructions for use, helpdesk troubleshooting).
Keep it up to date: The Use Specification is a living document that requires ongoing updates and maintenance throughout the sDHT development and usability validation process.

Regulatory Considerations
The development of the Use Specification is presented as the foundational step for the usability validation component of the V3+ framework. This document directly informs the subsequent Use-Related Risk Analysis.