The View of the Patient over Time
Until now, all of my posts have dealt with EHR user interface designs for a single patient encounter. In other words, they have been designs for displaying a snapshot of the patient’s health at a single point in time.
An electronic health record, however, is fundamentally a longitudinal record – a record that includes both the present and the past medical history. The record is updated as events, interventions, and health changes occur.
The electronic health record can be thought of as a cognitive tool for understanding and reasoning about these past and present health events to make the best decisions going forward. If you accept this premise, then in rethinking EHR design, even before considering usability or functionality, the most important question should be:
What user interface designs do the best job of presenting the patient’s past and present history and findings? How does a physician make sense of all the disparate information that accumulates in a patient’s chart over time?
There are two fundamentally different EHR user interface designs for presenting a patient’s story.
The design used by most EHRs places emphasis on the patient’s present state of health. In this design, each category of data (Problem List, Medications, Allergies, Procedures, and so forth) is maintained as a separate list. The lists are updated as events occur. Each event in a list has a start date associated with it – for instance, "Lipitor started 12/12/2008." Past events in the lists are indicated by stop dates or by designations such as "resolved" or "discontinued."
I might state this model formally as:
The patient’s current health information is the most important determinant of his or her future health. The patient’s current health status is best organized and understood as a set of categories that contain up-to-date lists of both present and past information. While it is essential to work with an up-to-date record of the patient’s current health problems, it is not necessary to be able to retrieve snapshots of what the record looked like in the past.
I believe, however, that both the patient and the physician think about the patient’s health very differently – as a series of inter-related events that unfold over time. It is fundamentally a story, a narrative of how things got to be the way they are. The story has the capacity to convey all the richness, complexity, and uniqueness of each patient.
A powerful way of telling and understanding the patient’s story is to present each point in time as a single screen view – a snapshot of the patient’s health at that time. The patient’s story can then be understood by stepping through the screen views in sequence, similar to turning the pages of a paper chart where each event or encounter is documented on a separate paper form which gets appended to the previous pages in chronological order (see my post on Why T-Sheets Work).
It’s also a little like turning the pages of a picture book or viewing the frames of a story board for a film – the patient’s story gradually unfolds.
I might state this model formally as:
The patient is a complex biological organism whose health changes over time. Every health event, intervention, procedure, and change in behavior potentially has an effect on all subsequent health events. The best way to comprehend the patient’s health issues is to treat the record as a narrative that unfolds over time and to present that narrative as a series of snapshots.
In the abstract, the difference between these two models may seem academic. In practice, there are profound implications for how easy or difficult it is to grasp and reason about a patient’s health issues. More on this in my next post …
Rick Weinhaus MD practices clinical ophthalmology in the Boston area. He trained at Harvard Medical School, The Massachusetts Eye and Ear Infirmary, and the Neuroscience Unit of the Schepens Eye Research Institute. He writes on how to design simple, powerful, elegant user interfaces for electronic health records (EHRs) by applying our understanding of human perception and cognition. He welcomes your comments and thoughts on this post and on EHR usability issues. E-mail Dr. Rick.