ISO/TR 13128:2012

TECHNICAL ISO/TR
REPORT 13128
First edition
2012-07-01
Health informatics — Clinical document
registry federation
Informatique de santé — Fédération d’enregistrement de documents
cliniques
Reference number
ISO/TR 13128:2012(E)
©
ISO 2012

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ISO/TR 13128:2012(E)
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ISO/TR 13128:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no longer
valid or useful.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TR 13128 was prepared by Technical Committee ISO/TC 215, Health informatics.
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ISO/TR 13128:2012(E)
Introduction
A federation of Clinical Document Registries (CDRs) provides a view that the entire set of member CDRs can
be seen as a single CDR. One can issue a federated query to any of the member CDRs and still receive the
consistent answer, which is in effect the same as the union of the individual answers from the CDRs. Therefore,
it offers a layer of location transparency.
Within a federation, a pair of CDRs can mutually agree to replicate the entire content of one CDR in the other CDR.
The original and replica are systematically synchronized to reflect any changes to the original ever since it was
replicated. This is called the “federated replication”. The key benefits of the federated replication are as follows.
a) It greatly enhances the availability and fault-tolerance of CDRs at the presence of a failure, which may
happen due to various kinds of catastrophic events such as fire, earthquake, flood, and even shortage
of network connectivity. When a failure of a CDR occurs and is detected, a query to the CDR can be
answered alternatively by another CDR if it maintains a federated replica of the failed CDR.
b) It also improves the performance of processing of federated queries. As previously stated, a federated
query can be sent to any of the member CDRs of the intended federation. If the receiving CDR maintains
a federated replica of another member CDR, it can answer the query using the replica without relaying it
to the original CDR, saving lots of network communication overheads.
The replication is done at the object level only. There is no specification as to how the replica can be used for
answering federated queries.
The primary goal of this Technical Report is to define a logical structure for the federation of CDRs (but not
repositories) that, therefore, does not require any conformance criteria, and to set out a list of basic functional
recommendations and configuration parameters for CDR federations, possibly with replication, as well as to
provide several use cases.
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TECHNICAL REPORT ISO/TR 13128:2012(E)
Health informatics — Clinical document registry federation
1 Scope
This Technical Report covers aspects of federations of Clinical Document Registries (CDRs) including cases
where the whole content of a CDR has been replicated in another CDR of the same federation. More specifically,
the following aspects are covered.
a) Recommendations for the creation and management of federations of CDRs and federation metadata.
b) Creation and management of federated replicas, including specifications to create, remove and maintain
federated replicas as well as metadata for them.
c) Use cases of federations with query processing examples, including various use cases of federations of
CDRs, together with examples of query processing policies to enhance the performance and fault-tolerance.
d) Processing of queries in the presence of federations and replicas: the presence of federated replicas might
affect the semantics of both local and federated queries. Informative examples to define exact behaviours
of processing the queries are given.
NOTE It is assumed that the problem of patient identification has been solved in a way that is beyond the scope of
this Technical Report, such as IHE XCPD (Cross-Community Patient Discovery) Profile. Some potential issues that will
not be addressed in this Technical Report include patient identity management, potential limitations of registries due to
jurisdictional policies or requirements, and how replicates are handled.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO/TS 27790, Health informatics — Document registry framework
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 27790 and the following apply.
3.1
registry federation
group of registries that have voluntarily agreed to form a union
NOTE 1 Such a federation may be based on common business interests and specialties that the registries may share.
NOTE 2 Registry federations appear as single logical registry to registry clients.
3.2
object replication
act of duplicating an object within a registry to another registry
3.3
object replica
duplicated copy of an object by object replication
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ISO/TR 13128:2012(E)
3.4
federated replication
act of duplicating a set of all objects within a registry to another registry belonging to the same federation
NOTE The original and duplicated set of objects should be maintained to be synchronized to each other.
3.5
federated replica
duplicated set of objects by federated replication
3.6
local query
query to a registry that has the limited range of search involving only the objects that have been originally
registered to the registry
NOTE It does not involve any replica that is duplicated within the registry or further relayed to other registries.
3.7
local query with replica
local query that has the range of search involving all objects residing in the registry, regardless of whether they
are original or duplicated, and that is not further relayed to other registries
3.8
federated query
query to a registry that has the range of search involving all objects within registries of the specified federation
NOTE The queried registry performs a local query (possibly with replica) and broadcasts the same query to all other
members of the federation, only as a local query (possibly with replica).
4 Symbols and abbreviated terms
ANSI American National Standards Institute
CDA Clinical Document Architecture
CDR Clinical Document Registry
ebXML Electronic Business Extensible Markup Language
HL7 Health Level 7
IHE Integrating Healthcare Enterprises
OASIS Organization for the Advancement of Structured Information Standards
HL7 RIM HL7 Reference Information Model
ebXML RIM ebXML Registry Information Model
RS Registry Service
SOAP Simple Object Access Protocol
XML Extensible Markup Language
5 Recommendations for federation
To be seen as a single CDR to a client, member CDRs of a federation should follow the following recommendations.
a) At least one of the registries forming a federation should be capable of creating one or more federations,
and all registries should be capable of joining one or more federations.
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ISO/TR 13128:2012(E)
b) A CDR should be capable of maintaining federation-related metadata consisting of metadata for the
federation itself and members of the federation. The membership metadata also includes information on
federated replicas.
c) Each CDR that is a member of a federation should maintain metadata about the federation of which
it is a member.
d) A CDR should be capable of creating, maintaining, and removing federated replicas.
e) Upon receipt of a federated query, a CDR should relay the query to other federation members based on
federation metadata and return combined results to the client.
f) A CDR should be able to take advantage of federated replica that it maintains, to enhance the performance
...