It is hard to underestimate the impact and importance of the
IHE (Integrating the Healthcare Enterprise). However, there are a lot of
unknowns and an under appreciation of the effect IHE has, especially on
potential workflow improvements and increases in efficiency. Therefore, I’ve
compiled this (limited) list of benefits. There are many more benefits than
listed here, but these are the most important. This is an abstract of an IHE
presentation at HIMSSME in April in Jeddah, Saudi Arabia. You can also watch a
video of the presentation
here.
|
The Interoperability Showcase was
very well attended |
1. To increase the chance of plug and play: In
general, the standards that form the foundation for the IHE have too many
options, the reason being that most of them are developed as part of a
semi-democratic process, which makes sure that all stakeholders (read vendors)
can be facilitated, i.e. none of them are greatly benefitted and none of them
severely handicapped by the choices that are made during the standardization
process. However, in practice, most people go overboard with creating these
standards such as DICOM and HL7. There is typically no thought given to determining
what is the minimum necessary, but rather, what “might be nice” to have. The
effect is that the ADT family of messages has grown to include 60 messages,
each of 20 segments, with an average of 30 fields, resulting in 600 data
elements. A similar feature creep has taken place with the DICOM standard,
where a work list at a modality can contain up to 120 attributes according to
the standard. IHE reduces these options greatly, for example, the IHE Scheduled
Workflow Profile (SWF) definition limits the 600 HL7 attributes to 39 as part
of 4 messages. The DICOM Worklist is also limited i.e. 42 instead of 120 attributes
are specified as part of the SWF profile.
2.
To reduce on-site testing: The connectathons,
where hundreds of vendor representatives get together for a week and test
literally thousands of use cases is definitely reducing the integration time
for these systems on-site. My guess is that the productivity for testing a
system at a connectathon is at least twice, if not higher, than having to
figure out the problem at a customer site. The other advantage is that these
test environments provide a level playing field, i.e. small vendors have an
equal opportunity to test their systems with one of the major players as the
big guys in this field. Another major by-product is the widespread availability
of test tools, test transactions and test images in the public domain that are
created as part of this effort and are available to test against.
3.
To provide a simple selection mechanism: I
always like to compare the IHE profiles with the fast food “value meal”
choices, i.e. instead of having to think about the exact configuration of your
hamburger and what type of sides or drink size, you can just pick a meal number.
Choosing IHE profiles is similar, instead of having to specify what list of
DICOM or HL7 transactions, and what attributes should be supported, one can
just specify “profile x.” The Scheduled Workflow (SWF) profile for the modality
actor is a good example. If a modality supports SWF, you can count on it
supporting the Modality Worklist, Storage, Modality Performed Procedure Step
and Storage Commitment functionality. There is only one (or at most a couple)
of boxes to check off when considering purchasing a device instead of having to
include pages of interface specification requirements.
4.
To eliminate gaps and overlaps in functionality:
In addition to the fact that no two RIS or PACS systems are equal, vendors also
like to come up with very creative non-descriptive names for their system
components. It is confusing for their customers who are wondering what exactly
a workflow manager, connectivity manager, intelligent router, gateway. or
broker does, and more importantly what it does NOT do. This also adds to the
current confusion on what is exactly a VNA does. If one is very specific about
which profiles are supported in what function, there is no confusion about, for
example, whether or not image deletions and corrections are automatically
communicated between a PACS and VNA using the IOCM (Information Object Change Management)
profile. Similarly, there is no confusion on whether one can connect a
univiewer to that same VNA using standard DICOM RESTful services for web access,
or that information that is archived is registered to a regional repository
using XDS. I understand the urge of vendors to use nice sounding names, but in
my opinion it confuses users more than it actually helps.
5.
To address workflow, including exceptions:
Integration profiles are defined based on real-life use cases. These use cases
address real-life problems such as the performance of an exam, creation of a
report, exchange of a discharge document, retrieval of a set of documents by a
physician, etc. To support these workflows, the IHE committee picks the minimum
necessary services and tools to do this in the most efficient manner. As a matter of fact, I would argue that if
every institution would implement these workflows and fully utilize their
features, there would be a major improvement in efficiency and productivity.
Knowing that real life situations do not always follow the same rules, there
are also several profiles defined to address exceptions and corrections to
reconcile patient information later on, or deal with unscheduled cases.
6.
To address display requirements: Communications
standards such as DICOM and HL7 typically do not focus on how information is
presented, but rather on the reliable exchange of the information. This causes
major issues with regard to performance and functionality. For example, the
capability of receiving digital mammography images at a workstation is useless
unless the same workstation is able to display these in exactly the order needed
for interpretation. In the case of digital mammography, the same view is
presented with one mirrored and displayed against each other with the chest
wand. In the case of nuclear cardiology the images are also displayed in a
certain order and one should be being able to change the different windows in a
specific way. Not only the presentation of the images is critical, the
persistency and consistency in greyscale and color rendering is even more
important. Modality specific profiles are created to address this issue.
7.
To re-enforce the standard: Some parts of the
standard were so poorly implemented that a profile definition that specifically
calls out these requirements is very helpful. This is the case with the Portable Data for Imaging (PDI) profile that addresses
the exchange of images on CD’s and DVD’s. This profile reiterates the
requirements as stated in the DICOM standard about making sure that there are
DICOM encoded images being exchanged, not some proprietary version of the
images, which can only be viewed by the embedded viewer, and that there is also
a DICOM DIR included providing a directory of the images stored on the media. A
related profile is the IRC profile that basically takes care of reconciling the
image information that is being imported in the PACS with a new or existing
patient, who can be uniquely identified without jeopardizing the information
integrity of the PACS.
8.
To provide a shared infrastructure platform: Many
applications have similar needs with regard to patient information management: security,
including access controls and audit trails, personnel management, such as the
availability of provider names, unique identifiers, and many more services that
can be shared, and more importantly, be implemented in a single standardized
manner. For example, there is no reason that an audit trail for a physician
accessing a diagnostic image should be implemented, recorded and accessed by a
system administrator differently than an audit trail for someone accessing a
lab result or any electronic medical record. Defining a unified set of profiles
to deal with this in the form of the ITI (IT Infrastructure) domain is a great
asset and will lead to efficiency because of its re-usability and economy of
scale.
9.
To provide enterprise and regional exchange
capabilities: Even though the information exchange mechanisms to the outside,
using cross enterprise document sharing profiles, is considered part of the ITI
(although for imaging it is included in the radiology domain), it is still
important enough to be mentioned separately on its own merits. Registration and
access of medical information is critical for the sake of patient safety, and
to reduce costs due to duplicate tests and procedures. In addition, we really
don’t know yet what the impact will be of having all that information available
for outcome measurements and decision support, but I am sure we will find a way
to use this “big data” in a way to benefit patients and improve the overall
efficiency of healthcare delivery.
10.
To exchange information about images: Using
DICOM, we can create a very simple object that refers to one or more other
objects such as images, and tell something about these objects in a standard
manner. It is encoded as a DICOM Structured Report (SR). A good application of
this feature is to point back to “key images” so that a physician knows which
images to review. This could be a major help during surgery, for example, to be
able to pull up just a few images out of a set of potentially thousands of
axial CT slices. Another application would be to exchange information between
an archive and any other location where there might be a copy of its images, to
determine if the image needs to be deleted, or replaced or changed in any way
for synchronization purposes.
This list of the top ten advantages or reasons to use IHE
could easily be larger but these are probably the most significant. Again, if
you are more of a visual or auditory learner, I suggest you check out the more
complete version of this write-up here. Details about the individual profiles
can also be found in my blog postings, you can just search for the appropriate
keywords, or at
OTpedia. Enjoy!