Introduction
Healthcare systems across the world are engaged in an epochal transition from paper to digital systems. A unifying and intuitive interface for the electronic patient record (EPR) has been an elusive goal for software developers and clinicians for decades. Paper is a technology for information transfer which has evolved over many centuries, with many powerful features which are well adapted to the human brain. Digital systems offer many advantages over paper, but they also bring many challenges in the organisation and presentation of clinical data to health professionals without resulting in data overload. Conventional electronic screen visualisation formats, which use tabs, dropdown menus, lists and multiple windows, present substantial comprehension challenges to end users. Digital systems for professional healthcare applications are as yet rarely developed to robust user interface standards to optimise them for the perceptual capabilities of the human user.1 2
The UK Government Digital Service has transformed our understanding of the principles of development of public sector information systems since 2010. It has placed prior discovery of the true needs of the end user at the centre of all digital system developments.3
‘Digital by Design’ enshrines the intent to make all Information Technology (IT) systems so functionally compelling and satisfying to use (‘Digital by Default’) that they will always be the user’s system of choice, rather than through organisational convenience and compulsion (‘Digital by Diktat’). It also enshrines the core principle that the benefits of digitisation lie not in replicating the paper process in code, but in new approaches to information management that deliver greater functionality than is possible with paper.
Computer-assisted data visualisation strategies in effective IT system design
The human occipital cortex subconsciously processes huge volumes of visual information with great speed and efficiency. It is wholly adapted to static and dynamic pattern recognition, recall and interpretation of shape, movement, colour, depth, distance and relative position. This biological truth is captured in the old aphorism that ‘one picture is worth 1000 words’. Edward Tufte4 has played a major part in advancing our awareness of the power of data visualisation.
Computer-assisted data visualisation is a fertile area for practical adaptation. The data deluge of the modern age mandates new approaches to the adaptation and presentation of digital information to the human brain, if the end user is not to be overwhelmed with digital noise.
Professor Ben Shneiderman, Dr Catherine Plaisant and their team at the Human Computer Interaction Laboratory (HCIL) of the University of Maryland in the 1990s reported an information architecture to support the visualisation of personal histories,5 which evolved into the HCIL Lifelines model for visualising a clinical history,6 which was not further exploited at the time.
Shneiderman’s ‘Mantra’ of data visualisation7 sets out the functional requirements of a system for the visualisation of a complex, large and/or heterogeneous data set. It distilled to the following system tasks: ‘Overview, Zoom, Filter, and Details-on-Demand’.8
The abstraction of knowledge, insight and actionable intelligence to drive optimal clinical decision making is rarely derived from one document or page in the individual clinical record. Instead, it often emerges from the temporal relationships of a number of documented events, in parallel with investigations and information on comorbidities, which tell a richer story.
Adaptation of the HCIL Lifelines model to our intent
We were particularly influenced by two projects in the 1990s from the HCIL Maryland team:
TheHCIL Filmfinder model9 showed us how to compress a large data set onto a single screen and how a single icon could be used to open a window to a large volume of content.
TheHCIL Lifelines model6 provided the conceptual framework for our concept of EPR.
The Lifelines concept describes a stacked and synchronised series of timelines on the Y axis of the interface, and time is plotted along the X axis. Interactive icons are displayed in time and place on the graphic, according to their allocated time and subject metadata.
In consequence, UHS Lifelines (UHSL) is dynamic both in time and in functional adaptability. The timeline evolves continuously, and new icons are added directly as the underlying documents are generated and authorised. New timelines can be added as new data sources on new subjects become available.
Lifelines and the University Hospital Southampton clinical data environment
The University Hospital Southampton (UHS) IT programme has considerable autonomy for innovation within the UK National Health Service (NHS) digital transformation programme. Since the mid-1990s, UHS has mandated a standard format for all clinical documents and reports. Consistent metadata on the source, subject field and date-time stamp has been applied to each item, according to a long-established clinical subject taxonomy (see box 1).
Document and data feeds into UHS Lifelines as of September 2018
UHS clinical disciplines supplying clinical documents to UHS Lifelines.
Surgery.
Medicine and elderly care.
Cancer care.
Trauma and orthopaedics.
Cardiovascular and thoracics.
Obstetrics, midwifery and gynaecology.
Child health.
Ophthalmology.
Emergency department.
Neurosciences.
Dermatology.
Clinical documents from partner healthcare units.
The local independent sector treatment centre (run by Care UK).
Southern Health NHS Trust (community health services in Hampshire).
Solent NHS Trust (community health services in Hampshire).
Departmental results of tests and imaging.
Histopathology and cytopathology reports.
Endoscopy attendances.
Nuclear medicine reports.
Radiology reports (including plain X-rays, CT, MRI, mammograms and ultrasound scans).
Administrative information.
Records of hospital inpatient admissions (from our patient administration system).
Miscellaneous administrative documents.
NHS, National Health Service; UHS, University Hospital Southampton.
By 2009, the hospital had amassed a large quantity of clinical documents and reports on more than two million patients. However, the clinical user experience of the IT system had not kept pace. Digital documents were primarily accessed through standard legacy computer interfaces. These make for a slow and taxing user experience in clinical service, when large volumes of time-structured information from multiple subject fields need to be assimilated and acted on in a short time frame.
We recognised the potential of the HCIL Lifelines model as a core framework for our evolving EPR. In this paper, we describe the development of the resulting clinical data visualisation system, the UHSL, which:
Offers overview, zoom, filter and details on demand functionality.
Is truly ‘Digital by Design’ through its relentless focus on end-user optimisation.
Substantially simplifies the challenges of clinical data visualisation of longitudinal data over decades from many subject fields.