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The Imperial Clarify, Design and Evaluate (CDE) approach to mHealth app development
  1. Maximilian Johnston1,2,
  2. Mohammad Mobasheri1,
  3. Dominic King1,2,
  4. Ara Darzi1,2
  1. 1The HELIX Centre, Institute for Global Health Innovation, Department of Surgery & Cancer, Imperial College London, London, UK
  2. 2Patient Safety Translational Research Centre, Department of Surgery & Cancer, Imperial College London, London, UK
  1. Correspondence to Dr Maximilian Johnston, Centre for Patient Safety & Service Quality, 5th floor, Wright Fleming Building, Norfolk Place, London W2 1PG, UK; m.johnston{at}

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Mobile health (mHealth) is the practice of using mobile phones and other wireless devices in healthcare. There has been an unprecedented wave of innovation at the intersection of healthcare and technological innovation, and new digital healthcare solutions hold the promise of transforming healthcare delivery. Despite great enthusiasm for digital solutions, there have been ongoing concerns regarding a lack of clinician involvement, end-user engagement and the lack of a robust evidence base, underpinning the development of many apps.1 Also, a lack of supporting frameworks to help development teams create useful and well-designed apps has hindered their practical usefulness, and subsequent success.

We present the Clarify, Design and Evaluate (CDE) framework, which has been developed and implemented at Imperial College London (figure 1). This framework aims to support the structured translation of an initial idea through to an effective app, the success of which has been rigorously evaluated. Our multidisciplinary team of clinicians, researchers, software developers and technologists at Imperial College London has broad experience in developing mHealth applications that have been developed through the framework. The aim of this article is to outline the development of two apps using the CDE approach so other innovators are aware of the requirement for well-conducted research, design and evaluation methods when implementing their apps in the future. The two apps we describe are (figure 2):

  • Hark: a clinical task management and collaboration platform that manages, and prioritises, clinical tasks for health organisations, providing an auditable track of all clinical activity.

  • Usher: a mobile-delivered platform to support patients going through complex patient pathways. Usher has been developed in the first instance for the bariatric surgery pathway at Imperial College Healthcare NHS Trust.

Figure 1

The Clarify, Design and Evaluate (CDE) approach to mHealth app development.

Figure 2

The Hark and …

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  • Twitter Follow Maximilian Johnston at @MaxJoJohnston

  • Contributors All authors conceived and designed the article. MJ, MM and DK drafted it. AD reviewed it for important intellectual content. All authors approved the final version.

  • Funding MJ, DK and AD are affiliated with the Imperial Patient Safety Translational Research Centre at Imperial College London, which receives centre funding from the National Institute for Health Research (Grant number 40490). The Higher Education Funding Council for England (HEFCE) funds the HELIX Centre (project code H10).

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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