title: A Mixed-Methods Approach to the Development, Refinement, and Pilot Testing of Social Networks for Improving Healthy Behaviors.
abstract: BACKGROUND
  Mobile health (mHealth) has shown promise as a way to deliver weight loss interventions, including connecting users for social support.
  
  
  OBJECTIVE
  To develop, refine, and pilot test the Social Pounds Off Digitally (POD) Android app for personalized health monitoring and interaction.
  
  
  METHODS
  Adults who were overweight and obese with Android smartphones (BMI 25-49.9 kg/m(2); N=9) were recruited for a 2-month weight loss pilot intervention and iterative usability testing of the Social POD app. The app prompted participants via notification to track daily weight, diet, and physical activity behaviors. Participants received the content of the behavioral weight loss intervention via podcast. In order to re-engage infrequent users (did not use the app within the previous 48 hours), the app prompted frequent users to select 1 of 3 messages to send to infrequent users targeting the behavioral theory constructs social support, self-efficacy, or negative outcome expectations. Body weight, dietary intake (2 24-hr recalls), and reported calories expended during physical activity were assessed at baseline and 2 months. All participants attended 1 of 2 focus groups to provide feedback on use of the app.
  
  
  RESULTS
  Participants lost a mean of 0.94 kg (SD 2.22, P=.24) and consumed significantly fewer kcals postintervention (1570 kcal/day, SD 508) as compared to baseline (2384 kcal/day, SD 993, P=.01). Participants reported expending a mean of 171 kcal/day (SD 153) during intentional physical activity following the intervention as compared to 138 kcal/day (SD 139) at baseline, yet this was not a statistically significant difference (P=.57). There was not a statistically significant correlation found between total app entries and percent weight loss over the course of the intervention (r=.49, P=.19). Mean number of app entries was 77.2 (SD 73.8) per person with a range of 0 to 219. Messages targeting social support were selected most often (32/68, 47%), followed by self-efficacy (28/68, 41%), and negative outcome expectations (8/68, 12%). Themes from the focus groups included functionality issues, revisions to the messaging system, and the addition of a point system with rewards for achieving goals.
  
  
  CONCLUSIONS
  The Social POD app provides an innovative way to re-engage infrequent users by encouraging frequent users to provide social support. Although more time is needed for development, this mHealth intervention can be disseminated broadly for many years and to many individuals without the need for additional intensive in-person hours.
authors.affiliation: Arnold School of Public Health, Department of Health Promotion, Education, and Behavior, University of South Carolina, Columbia, SC, United States. bridges5@mailbox.sc.edu.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0003-1791-0521
authors.initials: S
authors.lastname: Hales
authors.forename: Gabrielle
authors.identifier: http://orcid.org/0000-0002-1683-5729
authors.initials: G
authors.lastname: Turner-McGrievy
authors.forename: Arjang
authors.identifier: http://orcid.org/0000-0001-6220-1471
authors.initials: A
authors.lastname: Fahim
authors.forename: Andrew
authors.identifier: http://orcid.org/0000-0002-6465-9061
authors.initials: A
authors.lastname: Freix
authors.forename: Sara
authors.identifier: http://orcid.org/0000-0003-4992-4610
authors.initials: S
authors.lastname: Wilcox
authors.forename: Rachel E
authors.identifier: http://orcid.org/0000-0001-5493-4894
authors.initials: RE
authors.lastname: Davis
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-6448-7976
authors.initials: M
authors.lastname: Huhns
authors.forename: Homayoun
authors.identifier: http://orcid.org/0000-0002-1581-3464
authors.initials: H
authors.lastname: Valafar
keywords: mHealth; obesity; social cognitive theory; social support; weight loss