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.
