The Overview-by-Category Design
We have been considering two alternative high-level EHR designs for organizing a patient’s data over time – the Snapshot-in-Time design and the Overview-by-Category design.
In a recent post, I made the argument that the Snapshot-in-Time design supports our mental model of how a dynamic system, such as a patient’s state of health, changes over time.
In my last post, I proposed that the user interface (UI) that results from the Snapshot-in-Time design supports how the human visual system takes in and processes information.
While the Snapshot-in-Time design is at the core of much paper-based medical charting (see Why T-Sheets Work), for a number of reasons — only some of them due to technical limitations — it has not been widely adopted as a high-level EHR design. Instead, most EHRs employ an Overview-by-Category design.
The Overview-by-Category design places emphasis on the patient’s present state of health. A single summary screen displays multiple categories of EHR data (History of Present Illness, Assessment and Plan, Medications, etc.) each as a separate pane or table containing time-stamped data from both present and past encounters.
In my opinion, the Overview-by-Category design has several fundamental limitations:
- The patient’s story does not unfold as a narrative.
- Significant cognitive and mouse / keystroke effort is required to make sense of how entries in the different categories fit together.
- The overview screen tries to convey too much information. To see details, the user either has to scroll within the tables (see The Problem with Scrolling), to scroll the overview screen itself, or to navigate to entirely different screens (see Humans Have Limited Working Memory).
To help compare the two designs, I have constructed mockups below based on the Overview-by-Category design, using exactly the same patient database that I used for the Snapshot-in-Time mockups in my last post.
The Overview-by-Category mockups below are based on a widely-used EHR. While these illustrations are for an ambulatory patient, similar designs are common in hospital-based EHR systems.
In order to see the mockups and read the accompanying text, enlarge them to full screen size by clicking on the ‘full screen’ button
in the lower right corner of the SlideShare frame below.
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.