CDS software
Clinical decision support (CDS) software covers apps that provide information or advice based on specific input data about the patient, and/or provide easy access to clinical guidelines or protocols. Systems using complex algorithms and other forms of artificial intelligence (AI) to provide specific "advice and information" to patients can easily morph into full diagnostic systems (i.e. medical devices) and this is where they can run into problems with the medical establishment.
In the UK, the issues were first brought forcibly to the public's attention by the 2018 BBC documentary 'Diagnosis on demand? The computer will see you now'. The issues were summed up perfectly by one of the contributors who spoke of a true clash of cultures: ".. on the one hand you have the technology world, silicon valley, move fast, break stuff; then you have the diligent, evidence-based, do-no-harm healthcare system". You can read the outcome here but let's just say it didn't end well for the IT supplier.
In the Autumn of 2018 the UK NHS published a position paper (Accelerating the use of AI in health and care) based on a survey of private health IT companies currently developing AI systems for the healthcare sector. The UK government obviously saw AI as a potential saviour in relieving the ever-growing pressure on NHS professionals, but several influential professional bodies (e.g. Royal College of General Practitioners), the main doctor's union (British Medical Association) and two of the UK's leading medical journals (e.g. British Medical Journal, The Lancet) all expressed serious concerns about the pace with which this largely unproven technology was being introduced.
Fast forward 7 years and where are we now? Well, things have calmed down somewhat and IT suppliers have learned lessons from the initial experiences. However, the implementation of AI-based systems has been extremely slow and - for a variety of reasons - UK waiting times for both primary and secondary care appointments have increased further.
In the medical specialties, things have faired better, with diagnostic radiology being a particular beacon. You can read more about radiology applications, along with the latest guidance from the UK MHRA, here.
In the U.S, the status of CDS software was changed in 2016 by the publication of the 21st Century Cures Act, which amended the statutory definition of a medical device. The key part of the CDS software definition relates to the independent checking of the software's output. Namely, if CDS software is being heavily relied upon to make clinical management decisions about an individual patient, then that software would be deemed intrinsically more risky and therefore much more likely to be deemed to be a medical device. Latest FDA guidance can be read here.
In the EU there is no separate SaMD category for mobile apps or CDS software, so the software either meets the MDR17 definition of a medical device or it doesn't. However, as is the case with traditional medical devices, certain mobile medical apps can pose potential risks that are unique to the characteristics of the platform on which the software runs. For example, the interpretation of radiological images on a mobile device could be adversely affected by the smaller screen size, lower contrast ratio and uncontrolled ambient lighting. The FDA has stated that it intends to take these platform-specific risks into account when deciding the appropriate degree of regulatory oversight for these devices.