title: Effects of Three Motivationally Targeted Mobile Device Applications on Initial Physical Activity and Sedentary Behavior Change in Midlife and Older Adults: A Randomized Trial.
abstract: BACKGROUND
  While there has been an explosion of mobile device applications (apps) promoting healthful behaviors, including physical activity and sedentary patterns, surprisingly few have been based explicitly on strategies drawn from behavioral theory and evidence.
  
  
  OBJECTIVE
  This study provided an initial 8-week evaluation of three different customized physical activity-sedentary behavior apps drawn from conceptually distinct motivational frames in comparison with a commercially available control app.
  
  
  METHODS
  Ninety-five underactive adults ages 45 years and older with no prior smartphone experience were randomized to use an analytically framed app, a socially framed app, an affectively framed app, or a diet-tracker control app. Daily physical activity and sedentary behavior were measured using the smartphone's built-in accelerometer and daily self-report measures.
  
  
  RESULTS
  Mixed-effects models indicated that, over the 8-week period, the social app users showed significantly greater overall increases in weekly accelerometry-derived moderate to vigorous physical activity relative to the other three arms (P values for between-arm differences = .04-.005; Social vs. Control app: d = 1.05, CI = 0.44,1.67; Social vs. Affect app: d = 0.89, CI = 0.27,1.51; Social vs. Analytic app: d = 0.89, CI = 0.27,1.51), while more variable responses were observed among users of the other two motivationally framed apps. Social app users also had significantly lower overall amounts of accelerometry-derived sedentary behavior relative to the other three arms (P values for between-arm differences = .02-.001; Social vs. Control app: d = 1.10,CI = 0.48,1.72; Social vs. Affect app: d = 0.94, CI = 0.32,1.56; Social vs. Analytic app: d = 1.24, CI = 0.59,1.89). Additionally, Social and Affect app users reported lower overall sitting time compared to the other two arms (P values for between-arm differences < .001; Social vs. Control app: d = 1.59,CI = 0.92, 2.25; Social vs. Analytic app: d = 1.89,CI = 1.17, 2.61; Affect vs. Control app: d = 1.19,CI = 0.56, 1.81; Affect vs. Analytic app: d = 1.41,CI = 0.74, 2.07).
  
  
  CONCLUSIONS
  The results provide initial support for the use of a smartphone-delivered social frame in the early induction of both physical activity and sedentary behavior changes. The information obtained also sets the stage for further investigation of subgroups that might particularly benefit from different motivationally framed apps in these two key health promotion areas.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01516411.
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, and Epidemiology Division, Department of Health Research & Policy, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Abby C
authors.identifier: http://orcid.org/0000-0002-7949-8811
authors.initials: AC
authors.lastname: King
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Hekler
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Grieco
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Winter
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Jylana L
authors.initials: JL
authors.lastname: Sheats
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Buman
authors.affiliation: School of Earth, Energy and Environmental Sciences, Stanford University, Stanford, California, United States of America.
authors.forename: Banny
authors.initials: B
authors.lastname: Banerjee
authors.affiliation: Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America.|Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Robinson
authors.affiliation: Department of Computer Science, School of Engineering, Stanford University, Stanford, California, United States of America.
authors.forename: Jesse
authors.initials: J
authors.lastname: Cirimele
mesh_terms: D000368:Aged; D004038:Diet, Reducing / Q000379:methods*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009042:Motivation; D057185:Sedentary Behavior; D000068997:Smartphone; D061217:Weight Reduction Programs / Q000379:methods*