The Multiple Meanings of Interoperability


William A. Hyman
Professor Emeritus, Biomedical Engineering
Texas A&M University,
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In this space the most common meaning of interoperability is that EHRs should be able to readily share or transfer information between them. Moreover that information should be fully compatible with the features of the receiving EHR such that the shared information is findable (or better yet obvious) and useable. In some large centrally controlled systems the sharing part is accomplished by there being a single EHR which includes all of a patient’s encounters with that system, although not necessarily their encounters with any other provider. Other large systems still maintain separate EHRs at each entity such that, for example, care in one hospital is not accessible to the hospital across the street that is owned and operated by the same system. The same inability to share information famously exists between the DOD and the VA, following their billion dollar failure to create an integrated system.

But there are other uses of the term interoperability. One is that medical devices should be able to automatically populate the local EHR with information. For this purpose many in the medical device and hospital network world have labored to make devices do this, since they don’t do it readily. This often requires “middleware” (third-party) systems to interface the device to the network and then to the EHR, often one device at a time. It is sometimes asserted by people who are doing this interfacing that it is to meet Meaningful Use (MU) although in most cases MU does not require such automation other than for imaging and lab results. Of course MU defines a minimum set of things that must be done and does not preclude other things.

Auto-population can seem attractive in that in principle it eliminates labor, delays, and transaction errors. In some cases it also eliminates the need for a human to look at the data and see if it at least makes sense before entering it. While this step is sometimes called validation this is a misnomer in that the user usually cannot know if the data is correct but only recognize if it is unreasonable. Overzealous auto-population from devices can also fill an EHR with information that has no immediate clinical value, and which is never looked at unless a need arises for a retrospective analysis.

Besides moving information to the EHR, device derived along with manual data transfer can also be used to create dashboards that visually integrate and display information from disparate devices. Bringing multiple device data together can also be used in principle to create “smart” alarms that look at several patient parameters rather than having each device alarm on only its own parameters. Multi-device data might also be part of Clinical Decision Support. A key issue here is how smart such a system really is.

Another use of the term interoperability is the idea that under some circumstances it would be useful to have medical devices communicate directly with each other. An example here is that when a ventilator is temporarily paused for imaging, the user can forget to turn the ventilator back on. If the imaging system could “tell” the ventilator when to pause and when to resume this would eliminate this type of use error. Another example is that a respiratory monitor could halt delivery of an opioid (as well as generate an alarm) if respiration was being compromised. The challenges here are creating the necessary interfaces and defining the algorithms such that they are safe and reliable across a wide spectrum of patients and events.

These different types of interoperability also present different types of cybersecurity concerns with such concerns also being too often not well distinguished. In general database security is different from medical device security which is different from network security.

In some ways these different types of interoperability overlap, or may overlap in the future, but for now they are largely separate and some care should be taken to be clear about what type of interoperability is being discussed.