Table 3.

Minimal and optimal target product profile characteristics focused on app characteristics, as defined by expert consensus process

App
Characteristics	Minimal requirements	Optimal requirements	Comments
System validation	The app has been validated in the intended implementation setting. There is evidence demonstrating: Valid clinical association (clinical output based on input data is supported by well-established or novel evidence) And analytical validation (input data are processed correctly into expected output data)	The app has been validated in the intended setting. There is evidence demonstrating: Valid clinical association (clinical output based on input data is supported by well-established or novel evidence) And analytical validation (input data are processed correctly into expected output data) And clinical validation (clinical safety or other meaningful outcome relevant to the intended use)	There is evidence that the system is based on evidence and working to achieve the intended use for the intended setting (See FDA’s SaMD clinical evaluation for current guidance20)
System access (public API)	Publicly available API for data access protected by authentication and authorisation. At a minimum, technical standards are adhered to	Optimally, HIE/HL7 standards are adhered to
Context configuration	Language: UN official languages  Local time  Local weights and measures	Same as minimal, and the following:  Option to customise to local official language  Other country preferences	Language can be a major barrier to the proper use of the tool for patient management and can lead to errors and misinterpretation
Customisation	Changes to the app, such as updates to the list of medicines and POCs available in the setting, can be made by the healthcare programme. Validation of this change shall be provided	Same as minimal
User access rights	Appropriate data access is provided based on specific roles		Roles may include data manager (facility supervisor) or data entry person (nurse)
Expert support	None	Built-in access to online/remote expert advice to assist in patient consultation via SMS, audio call and video conferencing
App training	On-site training	Same as minimal, and remote training and/or remote ‘Train the Trainer’
Internet availability	Functions offline (allows for service delivery and key workflows)  Allows automatic resynchronisation	Same as minimal, and trigger alerts on user device when data have not been synchronised for a long time	Internet connection can be very unstable, therefore the tool should work in offline mode so as to not disrupt the workflow of the user
Clinical data entry	Manual entry by the operator	Same as minimal, plus automatic upload of digital data (eg, from biosensors, medical devices)	Optimal: this allows external integration of other app modules, built-in and third-party apps and devices
Patient management recommendation	Consultation data are summarised and actionable recommendations provided (eg, treatment, referral, home care or follow-up)	Same as minimal, and recommendations are integrated in EMRs and HIS
Navigation	Sequential: the user follows a strict sequence of data input to reach a final recommendation	Non-sequential: the user can move in any direction through an assessment and change input data to reach a final recommendation
Workflow requirements to enable time-delayed POC data input	Ability for a user to perform multiple, simultaneous consultations, with pause and resume capability, to allow clinical and laboratory data entry	Same as minimal, plus ability to disable simultaneous workflow feature in settings with minimally skilled workers	This is particularly relevant for implementation in settings where testing and clinical consultations are performed in different locations
Task management	Multiple algorithms can be supported simultaneously in one application against a common data set		Can accommodate task-shifting capability, that is, multiple consultations can be opened at a time and patient profiles can be accessed using preset user access rights
Follow-up	None	Ability to retrieve patient information using patient registration information	The optimal implies data recoverability, also covered in the Data section
System malfunction protection	System malfunctions are made clear to the user
Scalability	The app shall allow high transaction volumes with complex workflows to cover primary care workforce at a national scale
Updates and versioning	Processes are in place to control any app changes (including algorithm version updates) and provide the appropriate and correct update to the user

API, application programming interface; EMR, electronic medical record; FDA, Food and Drug Administration; HIE, Health Information Exchange; HIS, health information system; HL7, Health Level 7; POC, point-of-care; SaMD, software as a medical device; SMS, short message service; UN, United Nations.