title: Implementation of behavior change techniques in mobile applications for physical activity.
abstract: BACKGROUND
  Mobile applications (apps) for physical activity are popular and hold promise for promoting behavior change and reducing non-communicable disease risk. App marketing materials describe a limited number of behavior change techniques (BCTs), but apps may include unmarketed BCTs, which are important as well.
  
  
  OBJECTIVE
  To characterize the extent to which BCTs have been implemented in apps from a systematic user inspection of apps.
  
  
  METHODS
  Top-ranked physical activity apps (N=100) were identified in November 2013 and analyzed in 2014. BCTs were coded using a contemporary taxonomy following a user inspection of apps.
  
  
  RESULTS
  Users identified an average of 6.6 BCTs per app and most BCTs in the taxonomy were not represented in any apps. The most common BCTs involved providing social support, information about others' approval, instructions on how to perform a behavior, demonstrations of the behavior, and feedback on the behavior. A latent class analysis of BCT configurations revealed that apps focused on providing support and feedback as well as support and education.
  
  
  CONCLUSIONS
  Contemporary physical activity apps have implemented a limited number of BCTs and have favored BCTs with a modest evidence base over others with more established evidence of efficacy (e.g., social media integration for providing social support versus active self-monitoring by users). Social support is a ubiquitous feature of contemporary physical activity apps and differences between apps lie primarily in whether the limited BCTs provide education or feedback about physical activity.
authors.affiliation: Department of Kinesiology, Pennsylvania State University, University Park, Pennsylvania.
authors.forename: Chih-Hsiang
authors.initials: CH
authors.lastname: Yang
authors.affiliation: Department of Kinesiology, Pennsylvania State University, University Park, Pennsylvania.
authors.forename: Jaclyn P
authors.initials: JP
authors.lastname: Maher
authors.affiliation: Department of Preventive Medicine, Northwestern University, Chicago, Illinois. Electronic address: conroy@northwestern.edu.
authors.forename: David E
authors.initials: DE
authors.lastname: Conroy
mesh_terms: D001521:Behavior Therapy / Q000379:methods*; D015444:Exercise; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D063731:Mobile Applications; D012944:Social Support