title: Guidelines and Recommendations for Developing Interactive eHealth Apps for Complex Messaging in Health Promotion.
abstract: BACKGROUND
  The now ubiquitous catchphrase, "There's an app for that," rings true owing to the growing number of mobile phone apps. In excess of 97,000 eHealth apps are available in major app stores. Yet the effectiveness of these apps varies greatly. While a minority of apps are developed grounded in theory and in conjunction with health care experts, the vast majority are not. This is concerning given the Hippocratic notion of "do no harm." There is currently no unified formal theory for developing interactive eHealth apps, and development is especially difficult when complex messaging is required, such as in health promotion and prevention.
  
  
  OBJECTIVE
  This paper aims to provide insight into the creation of interactive eHealth apps for complex messaging, by leveraging the Safe-D case study, which involved complex messaging required to guide safe but sufficient UV exposure for vitamin D synthesis in users. We aim to create recommendations for developing interactive eHealth apps for complex messages based on the lessons learned during Safe-D app development.
  
  
  METHODS
  For this case study we developed an Apple and Android app, both named Safe-D, to safely improve vitamin D status in young women through encouraging safe ultraviolet radiation exposure. The app was developed through participatory action research involving medical and human computer interaction researchers, subject matter expert clinicians, external developers, and target users. The recommendations for development were created from analysis of the development process.
  
  
  RESULTS
  By working with clinicians and implementing disparate design examples from the literature, we developed the Safe-D app. From this development process, recommendations for developing interactive eHealth apps for complex messaging were created: (1) involve a multidisciplinary team in the development process, (2) manage complex messages to engage users, and (3) design for interactivity (tailor recommendations, remove barriers to use, design for simplicity).
  
  
  CONCLUSIONS
  This research has provided principles for developing interactive eHealth apps for complex messaging as guidelines by aggregating existing design concepts and expanding these concepts and new learnings from our development process. A set of guidelines to develop interactive eHealth apps generally, and specifically those for complex messaging, was previously missing from the literature; this research has contributed these principles. Safe-D delivers complex messaging simply, to aid education, and explicitly, considering user safety.
authors: Department of Computing and Information Systems, Melbourne School of Engineering, The University of Melbourne, Parkville, Australia.
authors: Kayla Joanne
authors: http://orcid.org/0000-0003-0816-8986
authors: KJ
authors: Heffernan
authors: Shanton
authors: http://orcid.org/0000-0002-2163-3910
authors: S
authors: Chang
authors: Skye Tamara
authors: http://orcid.org/0000-0002-1716-9043
authors: ST
authors: Maclean
authors: Emma Teresa
authors: http://orcid.org/0000-0002-3046-7694
authors: ET
authors: Callegari
authors: Suzanne Marie
authors: http://orcid.org/0000-0002-6869-311X
authors: SM
authors: Garland
authors: Nicola Jane
authors: http://orcid.org/0000-0001-5513-8291
authors: NJ
authors: Reavley
authors: George Andrew
authors: http://orcid.org/0000-0001-9059-9966
authors: GA
authors: Varigos
authors: John Dennis
authors: http://orcid.org/0000-0003-2431-7902
authors: JD
authors: Wark
keywords: complex messaging; eHealth smartphone apps; interactive; mhealth; vitamin D