Grace O'Malley*, Temple Street Children’s University Hospital, Dublin, Ireland Noirin Curran, Human Factors Research Group, Department of Applied Psychology, University of College Cork, Cork, Ireland Amanda Burls, School of Health Sciences, City University London, London, United Kingdom Grainne Dowdall, Child Health Information Coordinator; Temple Street Children’s University Hospital, Dublin, Ireland Ivan Perry, Department of Epidemiology and Public Health, University College Cork, Cork, Ireland, Cork, Ireland Track: Research Presentation Topic: Web 2.0 approaches for clinical practice, clinical research, quality monitoring Presentation Type: Poster presentation Submission Type: Single Presentation Last modified: 2013-09-25

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Background: Obesity is a global epidemic with behavioural change approaches to improving nutrition, increasing physical activity level and reducing sitting time recommended as best practice in adolescence. Access to evidence-based treatment is limited however and portable technologies such as a smartphone applications may provide a useful platform to deliver such lifestyle interventions. No evidence-based validated application exists for obesity intervention.

Objective:
The current aimed to test the usability and quality of a smartphone application, which has been developed as an intervention for adolescents who are obese.

Methods:
Usability was defined in line with ISO 9241-11 as the extent to which the application could be used by adolescents who are obese to achieve specified tasks with effectiveness, efficiency and satisfaction while using the application as a behavior change tool. Ten adolescents (12-17 years, 3 girls) who had been treated for obesity (>98th centile for body mass index) at the Temple Street Children's University Hospital were recruited. Participants and their parents were informed about the study and signed age appropriate consents and assents. The study was approved by the Ethics Committee of Temple Street Children's University Hospital.
Participants were given eight tasks to complete in order to test the effectiveness of the application. A research assistant timed the user completing each task in order to test relative user efficiency of the application. The tasks required the user to 1) enter personal settings; 2) find and answer surveys; 3) create a message; 4) use the goal setting feature and 5-8) enter details regarding weight and height. Time scores were divided by the time taken by an expert user to complete the task. In exploration of user satisfaction, each participant completed the standardised Software Usability Measurement Inventory (SUMI) which measures five aspects of user satisfaction. Descriptive statistics were used to explore the mean relative user efficiency and SUMI scores.

Results:
Mean age and standard deviation was 14.6 ± 1.9 years. Adolescents completed all tasks successfully and the mean relative user efficiency scores were 1.7 s ± 1.3 s for task 1; 2.4 s ± 1.4 s for task 2; 2.5 s. ± 2.1 s. for task 3; 1.2 s. ± 0.8 s. for task 4; 2.2 s. ± 1.3 s. for task 5; 3.6 s. ± 1.7s. for task 6; 2.2 s. ± 1.2 s. for task 7 and 1.7 s. ± 1.3 s. for task 8.
See Table 1 for SUMI results. Users responded that they would mainly use the app. to monitor their growth over time, for motivation and for goal setting. All users described the app. as important for them.

Conclusions:
Adolescents found the smartphone application easy to use and SUMI results indicated that the application scored high on user satisfaction. The application showed good usability and will be tested for clinical effectiveness in a randomised controlled trial. The application offers advantages over existing applications in that it is an evidence-based tool for weight management; can be tailored to the individual, is interactive and incorporates secure social networking features for adolescents who are clinically obese.