Some 43 percent of iOS health apps and 27 percent of Android health apps are useful, according to a report from The Commonwealth Fund, which included an analysis of 945 iOS and Android health apps.

“Apps really can play an essential role in chronic disease health management for populations that really need them the most,” University of Michigan Medical School Assistant Professor Karandeep Singh, one of the study's lead authors, told MobiHealthNews. “When we take a snapshot of the app store, a very small percentage, or a reasonably small percentage of apps seem like they actually would be useful and relevant to those populations.”

The Commonwealth Fund targeted patient-facing apps that were designed for high-need, high-cost patients with chronic conditions. Researchers searched for apps in both app stores by using 26 search terms that covered 21 conditions, including alcohol, arthritis, asthma, bipolar, cancer, cognitive impairment, COPD, coronary artery disease, dementia, depression, diabetes, drug abuse, elderly, heart disease, and heart failure, among others. Researchers pulled the first 50 app search results from these queries. After removing duplicates, researchers had a list of 2,119 apps in the iOS and Android app store, 946 iOS apps and 1,173 Android apps.

They then removed apps that were not health-related, not patient-facing, or not in English. They also removed apps that were very similar, for example lite and pro versions of the same app. In the end, researchers had a list of 376 iOS apps and 569 Android apps, or 945 total.

Usefulness of the apps was assessed entirely on their descriptions in the app stores. The researchers used the description to determine how the app sought to engage its users and the relevance of the app to the patient population it targets. Other factors were the app's ratings and reviews, as well as the timing of its most recent update. Engagement was split into tiers. Providing educational information was at the bottom of the chart and supporting behavior change through rewards was at the top. Other engagement tactics included apps that remind or alert users, apps that record or track health information, and apps that display and summarize information.

About 6 percent of the iOS apps had limited engagement beyond just offering educational information, like an ebook. Researchers also found that of the iOS apps identified, 9 percent had bad reviews and ratings and 17 percent were last updated before 2014. Of the Android apps researchers found, 16 percent had limited engagement, 1 percent had bad reviews and ratings, and 35 percent were last updated before 2014.

“We identified a number of apps that seemed to have good engagement or on paper have a lot of different engagement functionality that didn’t translate into quality and didn’t translate into safety,” Singh said. “In the pursuit of that functionality, people were missing the quality and safety issues.”

In a follow up survey, The Commonwealth Fund plans to consider whether health apps offered reliable information, if they handled sensitive patient info well, and whether the app developer respected patient information privacy and security.