title: Apps of steel: are exercise apps providing consumers with realistic expectations?: a content analysis of exercise apps for presence of behavior change theory.
abstract: OBJECTIVE
  To quantify the presence of health behavior theory constructs in iPhone apps targeting physical activity.
  
  
  METHODS
  This study used a content analysis of 127 apps from Apple's (App Store) Health & Fitness category. Coders downloaded the apps and then used an established theory-based instrument to rate each app's inclusion of theoretical constructs from prominent behavior change theories. Five common items were used to measure 20 theoretical constructs, for a total of 100 items. A theory score was calculated for each app. Multiple regression analysis was used to identify factors associated with higher theory scores.
  
  
  RESULTS
  Apps were generally observed to be lacking in theoretical content. Theory scores ranged from 1 to 28 on a 100-point scale. The health belief model was the most prevalent theory, accounting for 32% of all constructs. Regression analyses indicated that higher priced apps and apps that addressed a broader activity spectrum were associated with higher total theory scores.
  
  
  CONCLUSIONS
  It is not unexpected that apps contained only minimal theoretical content, given that app developers come from a variety of backgrounds and many are not trained in the application of health behavior theory. The relationship between price and theory score corroborates research indicating that higher quality apps are more expensive. There is an opportunity for health and behavior change experts to partner with app developers to incorporate behavior change theories into the development of apps. These future collaborations between health behavior change experts and app developers could foster apps superior in both theory and programming possibly resulting in better health outcomes.
authors.affiliation: Brigham Young University, Provo, UT 84602, USA.
authors.forename: Logan T
authors.initials: LT
authors.lastname: Cowan
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Van Wagenen
authors.forename: Brittany A
authors.initials: BA
authors.lastname: Brown
authors.forename: Riley J
authors.initials: RJ
authors.lastname: Hedin
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Seino-Stephan
authors.forename: P Cougar
authors.initials: PC
authors.lastname: Hall
authors.forename: Joshua H
authors.initials: JH
authors.lastname: West
mesh_terms: D040421:Cell Phone; D015444:Exercise; D015438:Health Behavior; D006801:Humans; D012044:Regression Analysis; D012984:Software