**3. Validation of digital health**

Any method should take into consideration all five of the Availability Criteria of a technological tool. The Global Score of Mathews and his colleagues shows promise. The authors have completed a thorough review of the current state of validation of Digital Health. They feel that stakeholders have low confidence in Digital Health solutions due to a lack of an objective way to evaluate products. They propose an end-user requirements approach assessment across the four technological, clinical, usability, and cost domains. Their Digital Health Scorecard incorporates these four criteria, which they aggregate into a composite Global Score. We are presenting this as a means to determine the gross initial selection of Digital Health solutions. Individual scores can allow sufficient discrimination of particular products, identify where improvements are needed or gaps, and compare similar Digital Health solutions [7]. Focusing on a few is imperative as resources are usually scarce.

The Global Scorecard uses a multi-stakeholder approach that purportedly can objectively and rigorously evaluate solutions. It is comparable to methodologies used outside of Healthcare (such as Underwriter's Lab, which develops safety standards and uses pre-market testing, and Consumers' Reports, which relies on post-market evaluation). It appears flexible and dynamic enough to meet the demands of multiple stakeholders. For example, payers want more efficient use of resources, whereas providers want increased reimbursement. The current scorecard uses end-user requirements to determine the maximum impact on patients. This approach can be transparent, thorough, and standards-based [8]. It is currently being tested for validity in different studies.
