title: Health Behavior Theory in Physical Activity Game Apps: A Content Analysis.
abstract: BACKGROUND
  Physical activity games developed for a mobile phone platform are becoming increasingly popular, yet little is known about their content or inclusion of health behavior theory (HBT).
  
  
  OBJECTIVE
  The objective of our study was to quantify elements of HBT in physical activity games developed for mobile phones and to assess the relationship between theoretical constructs and various app features.
  
  
  METHODS
  We conducted an analysis of exercise and physical activity game apps in the Apple App Store in the fall of 2014. A total of 52 apps were identified and rated for inclusion of health behavior theoretical constructs using an established theory-based rubric. Each app was coded for 100 theoretical items, containing 5 questions for 20 different constructs. Possible total theory scores ranged from 0 to 100. Descriptive statistics and Spearman correlations were used to describe the HBT score and association with selected app features, respectively.
  
  
  RESULTS
  The average HBT score in the sample was 14.98 out of 100. One outlier, SuperBetter, scored higher than the other apps with a score of 76. Goal setting, self-monitoring, and self-reward were the most-reported constructs found in the sample. There was no association between either app price and theory score (P=.5074), or number of gamification elements and theory score (P=.5010). However, Superbetter, with the highest HBT score, was also the most expensive app.
  
  
  CONCLUSIONS
  There are few content analyses of serious games for health, but a comparison between these findings and previous content analyses of non-game health apps indicates that physical activity mobile phone games demonstrate higher levels of behavior theory. The most common theoretical constructs found in this sample are known to be efficacious elements in physical activity interventions. It is unclear, however, whether app designers consciously design physical activity mobile phone games with specific constructs in mind; it may be that games lend themselves well to inclusion of theory and any constructs found in significant levels are coincidental. Health games developed for mobile phones could be potentially used in health interventions, but collaboration between app designers and behavioral specialists is crucial. Additionally, further research is needed to better characterize mobile phone health games and the relative importance of educational elements versus gamification elements in long-term behavior change.
authors.affiliation: Computational Health Science Research Group, Department of Health Science, Brigham Young University, Provo, UT, United States. hannahp413@gmail.com.
authors.forename: Hannah E
authors.identifier: http://orcid.org/0000-0003-4109-1634
authors.initials: HE
authors.lastname: Payne
authors.forename: Victor Ba
authors.identifier: http://orcid.org/0000-0003-2323-4603
authors.initials: VB
authors.lastname: Moxley
authors.forename: Elizabeth
authors.identifier: http://orcid.org/0000-0002-2740-7383
authors.initials: E
authors.lastname: MacDonald
keywords: behavioral health; content analysis; health and fitness apps; mobile phone; physical activity; theory