Smartphone apps for insomnia: examining existing apps' usability and adherence to evidence-based principles for insomnia management.

Insomnia affects up to 22% of the U.S. adult population. The use of mobile health applications (mHealth apps) has been posited as one way to increase access to evidence-based interventions for insomnia, such as cognitive behavioral therapy for insomnia (CBT-I). The purpose of the current study was to summarize the availability of mHealth apps that focus on providing users with the behavioral and/or cognitive skills to manage insomnia, assess their adherence to evidence-based principles, and examine their usability. The terms "insomnia," "insomnia treatment," and "sleep treatment" were used to search the Apple iTunes and Google Play stores in November 2016. Social network query within the authors' professional networks was also conducted. Apps that met inclusion criteria for the study were downloaded and reviewed by the research team for their general characteristics; inclusion of CBT-I skills, strategies, and principles; and aesthetics and usability. Of the 357 apps initially found, 12 met criteria for further review. Overall, the apps were moderately adherent to CBT-I principles, with a mean app score of 1.44 out of 3.00, and moderately usable, with a mean usability score of 3.54 out of 5.00. Few apps currently exist that utilize evidence-based principles to help users practice the behavioral and cognitive skills shown to manage insomnia. Thus, there are exciting opportunities for clinicians, researchers, and mHealth experts to develop effective apps that can help ease the public health burden of insomnia.