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EHR Design Talk with Dr. Rick 7/23/12

Pane Management — Part 2

The human visual system evolved over tens of millions of years to help our ancestors keep track of and interact with real objects in the physical world. To the extent that an EHR user interface design can harness our finely honed visual-spatial capabilities, using it will be intuitive and nearly effortless, even though the "space" we are navigating is that of data and the "objects" we are manipulating are abstract concepts.

Unless acted upon, objects in our physical world don’t move around, get larger or smaller, or change their orientation in relation to other objects. The human visual system "understands" these properties of the physical world. We are very good at constructing mental maps of what we see and using those maps to keep track of how objects are organized in space.

Unfortunately, graphical user interface (GUI) designs are not bound by the laws of physics and the constraints of the physical world. When we manipulate one object on the screen, other screen objects, for no apparent reason, can disappear and suddenly re-appear in different locations or radically change their shape and orientation.

While we might enjoy an altered set of physical rules as part of the challenge of playing a video game, it would be disconcerting, to say the least, to encounter such behavior in an EHR user interface.

Consider the EHR design below, by a well-known healthcare software toolkit developer.

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Above is the physician’s home screen for a particular patient. Six panes are used to display six categories of patient data — Most Recent Activities, Medications, Patient Charts, Risks, Lifestyle, and Current Care. For clarity, I have enlarged the font size and drawn red boxes around the title bar of each pane.

Each pane is assigned to a particular location on the screen. One at a time, each pane can be expanded and then contracted by using the mouse cursor to click on the "maximize" button at the far right of its title bar (see Risks pane above).

So far so good. But look at what happens to the other panes below when I do expand one pane, such as the Risks pane (purple arrow). For clarity, I have significantly shortened the horizontal span of the screen in the next two figures:

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When I expand the Risks pane, all the other panes close so that just their title bars are displayed. Worse, they all change their position, size, and orientation. The Most Recent Activities pane (red arrow) and the Medications and Patient Charts panes (blue arrows) are now oriented vertically along the far left of the screen. The Most Recent Activities pane is twice the width of the others.

The Lifestyle and Current Care panes (yellow arrows) maintain their horizontal orientation and relative position, but have been shifted to the bottom of the screen and stretch along its entire extent.

If I need to expand another pane, such as the Medications pane (indicated by the blue arrow below), all the other panes again change their position, size, and orientation:

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With the Medications pane expanded, the Most Recent Activities pane (red arrow) is now oriented horizontally instead of vertically and extends along the entire top of the screen.

The Patient Charts pane (bottom blue arrow) keeps its vertical orientation, but now is displayed on the right side of screen, elongated to span the entire screen height. The Lifestyle and Current Care panes (yellow arrows) change from horizontal to vertical orientation as does the contracted Risks pane (purple arrow). In addition, the Lifestyle pane has been stretched vertically.

In fact, whenever any pane is expanded, the other, non-expanded panes somewhat arbitrarily change their position, size, and orientation in this way. This is a poor mapping. It doesn’t correspond to our mental model of the physical world. It doesn’t take advantage of our highly evolved ability to organize objects in visual space.

Instead of the design above, why not use a small overview map for orientation and navigation, as in the figure below?

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This is a more natural mapping. The positions of the six panes in this small overview map correspond to those of the home screen (first figure) and those positions remain constant regardless of which pane is expanded. Furthermore, this overview map (overlaid below, for comparison, in the lower right corner of the expanded Risks pane) takes up less than 3% of the screen area, whereas the vendor’s design (outlined by the yellow border below) uses almost 20%:

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It’s not that physicians and other users can’t work with problematic EHR interfaces such as this one. Humans are remarkably adaptable and flexible, but it requires cognitive effort. It’s not just the extra second or so that it takes to find a pane in its new location. That’s the least of it.

The real problem is that, unlike computers, humans have extremely limited working memory. Having to deal with the shifting location, size, and orientation of data objects is disorienting.

Whenever we use a slot in our visual working memory for these kinds of tasks, we can no longer use that slot for clinically relevant information. It’s easy to underestimate how much this kind of EHR interface can interfere with our ability to make sense of complex patient data in the clinical setting.

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.