Interoperability
July 25, 2007
This information is intended to serve as a
general resource and does not constitute legal advice. If you need legal
advice, please consult an attorney.
There has been much public discussion and hype about the state of
health information technology system interoperability. Interoperability
is defined as the connection between diverse systems and almost all EMR
vendors claim to adhere to interoperability standards. Often, terms such
as HL7, CDA, CCD, CCR, etc. are bandied about as the panacea for health
information interoperability when in reality, the ability to interface
systems is overpromised, under delivered, and costly. Below, you
will find a description of each of these standards.
The US government, under the auspices of Health and Human Services
(HHS) via the Office of the National Coordinator for Health Information
Technology (ONCHIT), funded a group of private and public stakeholders
to form the Healthcare Information Technology Standards
Panel (HITSP) with the objective of certification of
interoperability standards. HITSP is sponsored by American National
Standards Institute (ANSI) in conjunction with other partners such as
the Healthcare Information and Management Systems Society (HIMSS), the
Advanced Technology Institute (ATI) and Booz Allen Hamilton. The initial
list of HITSP approved standards were published in 2006 and while this
achievement represents a step forward, true interoperability remains a
distant dream.
Vendors may use some version of any of the above mentioned standards
and claim interoperability. The truth is that vendors store data in
proprietary database structures that aren’t compatible with
competing vendors. Different uses of Electronic Health Record (EHR)
systems drive the need to interface with other health information
technology systems (e.g. lab, transcription, practice management). Many
of these uses require event triggered assured delivery of computer-only
readable data items such as lab results using HL7 while other uses
require a human and computer readable patient record summary and plan of
care for referral to an unknown provider’s system using a
Continuity of Care Record (CCR).
The most important consideration for interoperability in an EHR
vendor is to ensure that the vendor has experience creating interfaces
with the systems that require interoperability in your particular
situation. Interfaces by their nature are one direction only and there
are many cases where bidirectional interfaces are needed and require two
interfaces to achieve full interoperability (e.g. integration of a
Practice Management System (PMS) with an EHR with ability to change
demographic information in either system that updates in both). There is
no one standard that solves the interoperability problem, though the
most common interface standards are described below.
What is the CCR?
The Continuity of Care Record (CCR) is a standard
specification developed jointly by ASTM (American Society for Testing
and Materials) International, the Massachusetts Medical Society (MMS),
and the Health Information Management and Systems Society (HIMSS) in
2004. It is intended to foster and improve continuity of patient care
and to assure at least a minimum level of quality when a patient is
referred, transferred, or otherwise goes to another provider setting.
The origins of the CCR stem from a Massachusetts Department of Public
Health, three-page, NCR paper-based Patient Care Referral Form that has
been in widespread use over many years in Massachusetts.
The CCR standard is a patient health summary document. It is a way to
create flexible, portable documents that contain the most relevant and
timely health information about a patient. The resulting documents can
easily be sent electronically from one provider to another or even be
reasonably read by human eyes. The CCR contains sections such as patient
demographics, insurance information, diagnosis and problem list,
medications, allergies and care plan. These represent a "snapshot" of a
patient's health data that can be useful or possibly lifesaving, if
available at the time of clinical encounter. The ASTM CCR standard is
designed to permit easy creation by a physician using an electronic
health record (EHR) system at the end of an encounter.
Because it is expressed in the standard data interchange language
known as XML, a CCR can potentially be created, read and interpreted by
any EHR and EMR software applications. A CCR can also be exported in
other formats, such as PDF and Microsoft Word format. CCR is not
typically utilized to transmit transactional health data but is rather
used as a record summary snapshot and is the preferred standard for many
PHR (Personal Health Record) systems. CCR is supported by a wide array
of ambulatory EMR vendors but has not penetrated the inpatient EMR
market.
What is HL7?
Health Level Seven,
Inc. (HL7), is an all-volunteer, not-for-profit organization
involved in development of international healthcare standards.
“HL7” is also used to refer to some of the specific
standards created by the organization (i.e., HL7 v2.x, v3.0, HL7
RIM).
HL7’s primary mission is to create flexible, low-cost
standards, guidelines, and methodologies to enable the exchange and
interoperability of electronic health records.
HL7 Messaging Standards
All messaging standards define how information is packaged and
communicated from one party to another. Such standards set the language,
structure and data types required for seamless integration from one
system to another. HL7 v2.x and v3.x messages are transactional in
nature and are typically triggered by events (such as admission,
transfer, discharge, lab order or result). Messages carry a payload
specific to the triggering event (such as a single lab result, a
demographic change, text of a transcription) rather than a patient
record summary. HL7 messages typically require acknowledgement from the
receiving system thus assuring delivery.
HL7 v2 Messaging
HL7 v2.x is the original and widely adopted health-related Electronic
Data Interchange (EDI) standard. This delimited text messaging format
was created in the mid 1990’s and has incrementally been updated
on an almost ad-hoc basis ever since.
A weakness in the flexible HL7 v2 standard is the lack of ability to
test conformance because it is a text-based standard with weak data
types and too many ad-hoc additions. This has lead to less than optimal
interoperability between systems as HL7 interface analysis, testing, and
significant development are often required to create functional
interfaces.
HL7 v2 has achieved wide adoption and is supported by virtually every
EMR in the United States in ambulatory and inpatient settings. HL7 v2 is
commonly used to transmit patient demographic and scheduling data
between systems and is the primary means by which laboratory data is
transmitted between health information technology systems.
HL7 v3
HL7 v3 addresses the weakness in v2.x by utilizing a reference
information (i.e., data) model for messaging. It is the most definitive
HL7 standard to date. Using rigorous analytic and message building
techniques and incorporating more trigger events and message formats
with very little optionality, HL7's primary goal for v3 is to offer a
standard that is definite and testable, and provide the ability to
certify vendors' conformance using XML standards. V3 uses an
object-oriented development methodology and a Reference Information
Model (RIM) to create messages. The RIM is an essential part of the HL7
v3 development methodology, as it provides an explicit representation of
the semantic and lexical connections that exist between the information
carried in the fields of HL7 messages. HL7 v3 was first developed in
2000 enjoys success in Europe but has not achieved wide adoption in the
United States.
CCD
The Continuity of Care Document (CCD) is HL7’s patient health
summary record. The CCD standard was approved by HL7 in January, 2007.
This standard represents harmonization between HL7’s Clinical
Document Architecture (CDA) and ASTMs Continuity of Care Record (CCR),
both XML-based standards. CCD describes how to implement the CCR dataset
with the standard architecture for clinical records developed by
HL7.
Development of the CCD represents the joint efforts of HL7 and the
E31 Healthcare Informatics Committee of ASTM International, which had
led efforts to develop a standardized continuity of care record.
There is no means by which CCR can easily be transformed into CCE
(and vice versa), somewhat limiting the utility of this harmonization.
CCD is a new standard with HITSP support but has yet to penetrate either
the ambulatory or inpatient EMR marketplace. CCD, like CCR, captures a
snapshot of patient information and could be used for a PHR or to create
a portable snapshot to improve continuity of care between providers.
Resources:
Some information on this document from Wikipedia, HL7, ASTM, and
HITSP.
| interoperability, health information technology |
| 
