Introduction

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.