V3+ extends the V3 framework to ensure user-centricity and scalability of sensor-based digital health technologies

Abstract

We propose the addition of usability validation to the extended V3 framework, now "V3+", and describe a pragmatic approach to ensuring that sensor-based digital health technologies can be used optimally at scale by diverse users. Alongside the original V3 components (verification; analytical validation; clinical validation), usability validation will ensure user-centricity of digital measurement tools, paving the way for more inclusive, reliable, and trustworthy digital measures within clinical research and clinical care.

Fig. 1. From V3 to V3+.

The V3+ framework includes four components, with usability validation as the latest addition. Although depicted sequentially, V3+ is a modular framework as shown in Fig. 5. sDHT sensor-based digital health technologies. See Table 1 for definitions.

Fig. 2. The four key activities of the usability validation component of V3+.

This figure depicts the four usability validation activities of V3+ in the order in which they are typically undertaken, as well as the approximate alignment with verification, analytical validation, and clinical validation. Importantly, usability validation is rarely linear, and therefore the timing and order of activities will vary case-by-case. See Table 1 for definitions. *The intended use statement is a key component of the labeling of regulated medical devices. We recommend development of an equivalent statement for non-regulated sDHTs.

Fig. 3. Relationships between the elements of a use-related risk analysis.

A use-error is an action or lack of action which may result in a use-related hazard. An error that does not lead to foreseeable harm does not need to be described in the use-related risk analysis; however, such errors should be accounted for to optimize usability. See Table 1 for definitions. The three examples illustrated in this figure relate to the end-users of sDHTs; however, use-errors apply to all sDHT users including carepartners, clinicians, researchers, and administrators.

Fig. 4. The three V3+ usability validation activities applicable to post-market sDHTs.

This figure depicts the subset of V3+ usability validation activities that are applicable to post-market sDHTs, during which there is no immediate opportunity to modify the technical specification, product design, or undertake formative evaluation. See Table 1 for definitions. *The context of use statement is a key component of the labeling of regulated medical devices. We recommend development of an equivalent statement for non-regulated sDHTs. This statement should be compared against the original intended use (or equivalent statement) of the sDHT; this gap analysis will guide subsequent activities.

Fig. 5. V3+ in action.

This figure is an expanded version of Fig. 3 in ref. , emphasizing the modular nature of V3+; that is, changes made within one component of the framework will require repeat testing or documentation of generalizability of that component, but may not always require repetition of the full evidence stack.