Apps to promote physical activity among adults: a review and content analysis

International Journal of Behavioral Nutrition and Physical Activity Apps to promote physical activity among adults: a review and content analysis Anouk Middelweerd 0 Julia S Mollee 2 C Natalie van der Wal 1 2 Johannes Brug 0 Saskia J te Velde 0 0 Department of Epidemiology & Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center , Van der Boechorststraat 7, 1081 BT Amsterdam , The Netherlands 1 Department of Psychology, VU University Amsterdam , De Boelelaan 1081, 1081HV Amsterdam , The Netherlands 2 Department of Computer Science, VU University Amsterdam , De Boelelaan 1081, 1081HV Amsterdam , The Netherlands Background: In May 2013, the iTunes and Google Play stores contained 23,490 and 17,756 smartphone applications (apps) categorized as Health and Fitness, respectively. The quality of these apps, in terms of applying established health behavior change techniques, remains unclear. Methods: The study sample was identified through systematic searches in iTunes and Google Play. Search terms were based on Boolean logic and included AND combinations for physical activity, healthy lifestyle, exercise, fitness, coach, assistant, motivation, and support. Sixty-four apps were downloaded, reviewed, and rated based on the taxonomy of behavior change techniques used in the interventions. Mean and ranges were calculated for the number of observed behavior change techniques. Using nonparametric tests, we compared the number of techniques observed in free and paid apps and in iTunes and Google Play. Results: On average, the reviewed apps included 5 behavior change techniques (range 2-8). Techniques such as self-monitoring, providing feedback on performance, and goal-setting were used most frequently, whereas some techniques such as motivational interviewing, stress management, relapse prevention, self-talk, role models, and prompted barrier identification were not. No differences in the number of behavior change techniques between free and paid apps, or between the app stores were found. Conclusions: The present study demonstrated that apps promoting physical activity applied an average of 5 out of 23 possible behavior change techniques. This number was not different for paid and free apps or between app stores. The most frequently used behavior change techniques in apps were similar to those most frequently used in other types of physical activity promotion interventions. Mobile phone application; Behavior change technique; Physical activity; Smartphone - Background Physical inactivity contributes to approximately 3.2 million deaths annually and is the fourth leading risk factor for premature death [1,2]. Despite the fact that many people do not comply with physical activity recommendations [1,3], smartphone applications (apps) that promote physical activity are popular: of the 875,683 active apps available in iTunes and the 696,527 active apps in Google Play, 23,490 and 17,756 were categorized as Health and Fitness [4,5]. Therefore, it is worthwhile to study the potential of apps that aim to promote physical activity, especially because 56% of the US adults owns a smartphone [6]. Health behavior change interventions are more likely to be effective if they are firmly rooted in health behavior change theory [7-9]. Webb et al. [7] have noted the importance of behavior change theories in Internetbased interventions. Additionally, earlier studies have suggested that individually tailored feedback (i.e., feedback based on the users own characteristics [10]) and advice is more likely to be effective than generic information about physical activity [9,11,12]. Many advantages of using the Internet as a delivery mode apply to smartphone apps too: constantly accessible, adjustable to the needs of the user [13], able to provide (computer-) tailored feedback, large reach and interactive features. Because people carry smartphones and can access data anywhere and anytime, physical activity behavior change promotion apps offer the opportunity to provide tailored feedback and advice at the appropriate time and place. Therefore, apps offer new opportunities to deliver individually tailored interventions, including real-time assessment and feedback that are more likely to be effective. Apps are relatively new tools in physical activity interventions and only very little research has been published to date on the content and the effectiveness of physical activity apps. It remains unclear to what extent apps differ in their relevant content and if these differences mediate effectiveness. Previous research suggests that the use of behavior change techniques to address behavioral determinants conceptualized in behavior change theory, is linked to effectiveness [14]. Therefore, it can be proposed that the presence of behavior change techniques in general and some specific behavior change techniques in particular is an indicator of potential effectiveness. Abraham and Michie [14] developed a taxonomy to identify behavior change techniques in a range of health promotion interventions. The taxonomy can be used to identify techniques or combinations of techniques that enhance effectiveness. The most frequently applied behavior change techniques in traditional interventions are goal-setting [14], prompt intention formation [14], providing feedback on performance [14], self-monitoring [14] and reviewing behavioral goals [15,16]. A large body of work has been published using the taxonomy in health promotion interventions [7,15-17], but so far, no study has been conducted with the aim to review application of behavior change techniques in apps. Therefore, the present study aims to review apps developed for iOS and Android that promote physical activity among adults through individually tailored feedback and advice. Recent reviews have concluded that health promoting apps lack the use of behavior change theories in promoting behavior changes such as smoking cessation, weight-loss, and increased physical activity [18-21]. Only one earlier study focused on the use of behavior change theories in apps that target physical activity [18]. However, the authors limited their search to iTunes and excluded apps that targeted other health behaviors in addition to physical activity (e.g. apps that combined physical activity and diet information). Another limitation of their review was that it included apps that only provided information or solely used GPStracking to promote physical activity. In addition, the authors used a first generation iPad to download and review the apps and consequently had to exclude apps that were not compatible with this tablet. To improve upon the existing body of research on this topic, the current study reviews the use of behavior change techniques in physical activity apps available in both app stores (i.e., iTunes and Google Play) restricted to apps that utilize tailored feedback. Because previous studies reported a significant association (...truncated)