How do we know whether medical apps work?

Angry Birds, Cut the Rope, and Fruit Ninja are favourite games among smartphone owners, but many apps are for function rather than fun, such as maps and shopping lists, and a host of medical apps that say they offer us ways to better health.

Some are aimed at healthcare professionals but are available to all. The National Institute for Health and Clinical Excellence (NICE), the Scottish Intercollegiate Guidelines Network, and the British National Formulary have free apps allowing easy and rapid access to their advice. But other apps do not just reproduce advice available elsewhere. In January the UK Medicines and Healthcare Products Regulatory Agency (MHRA) approved its first app: Mersey Burns is a free tool that calculates burn area percentages and fluid requirements.

Other medical apps are aimed at the public. Many advise on diet and exercise, and these vary widely in quality,1 2 but newer apps purport to help diagnosis. The NHS Healthcare Innovation Expo this month featured an app from Skin Analytics that offers to track changes in skin moles to “raise early warning signs” by comparison with an online database.3 Its website says that, for £30 a year for an individual or £50 for a family, the app can “baseline you and your family” using “patent pending technology” that …