1、 ISO 2012 Health informatics Clinical document registry federation Informatique de sant Fdration denregistrement de documents cliniques TECHNICAL REPORT ISO/TR 13128 First edition 2012-07-01 Reference number ISO/TR 13128:2012(E) ISO/TR 13128:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTE
2、D DOCUMENT ISO 2012 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs membe
3、r body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO/TR 13128:2012(E) Foreword ISO (the International Organization for Standardization) is a wor
4、ldwide 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
5、 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
6、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 Standar
7、d 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 ma
8、jority 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is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful.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
9、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. ISO 2012 All rights reserved iii ISO/TR 13128:2012(E) Introduction A federation of Clin
10、ical 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. Therefo
11、re, 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 ca
12、lled 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 sho
13、rtage 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 federa
14、ted 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
15、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 c
16、riteria, 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. iv ISO 2012 All rights reserved Health informatics Clinical document registry federation 1 Scope This Technical Rep
17、ort 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
18、 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,
19、 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
20、 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 addres
21、sed 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
22、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 T erms and definitio ns For the purposes of this document, the terms and definiti
23、ons 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 l
24、ogical 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 TECHNICAL REPORT ISO/TR 13128:2012(E) ISO 2012 All rights reserved 1 ISO/TR 13128:2012(E) 3.4 federated
25、 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
26、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 lo
27、cal 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 registri
28、es 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
29、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 eb
30、XML 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 for
31、ming a federation should be capable of creating one or more federations, and all registries should be capable of joining one or more federations. 2 ISO 2012 All rights reserved ISO/TR 13128:2012(E) b) A CDR should be capable of maintaining federation-related metadata consisting of metadata for the f
32、ederation 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 removi
33、ng 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 o
34、f query processing. The CDRs that form a federation in principle are assumed to be heterogeneous. Therefore the above recommendations demand additional capabilities and interfaces to existing (local) registries. The metadata associated with federation should not be confused with metadata associate w
35、ith documents A CDR federation can be either centralized or decentralized. In a centralized federation, there is an agent (either one of the member CDRs or a separate entity) that is in charge of maintaining federation-related metadata and routing federated queries. On the other hand, in a decentral
36、ized federation, all member CDRs act as agents on their own. 6 Modes of federated replication Federated replication can be configured several different ways depending upon the following parameters. First, the replication can be either partial or full. In a partial replication, only part of the conte
37、nt of a CDR is replicated to another CDR, while the whole content is replicated in the full replication mode. Second, the replication can be updated in real-time or scheduled batch mode. In the former, any changes in the content of a CDR including additions, deletions, or updates of registry objects
38、 are immediately reflected to the replica as well. In the latter, the changes are logged and the reflection is delayed until a pre-determined time, after which it is completed. Third, the replication can be done either in a hierarchical or peer-to-peer (P2P) fashion. In the hierarchical mode, member
39、 CDRs are arranged as a tree and the content of a CDR is only replicated to its predecessors in the hierarchy. On the other hand, in the P2P mode, the content of a CDR is replicated to one or more CDRs that have been designated as peers in advance. 7 Use cases for federation This clause describes so
40、me of the use cases where the CDR federation (with or without replication) plays an important role. 7.1 Clinical document sharing via regional federation without replication Healthcare providers located in a specific region may wish to form a network with a tertiary hospital as the regional centre s
41、o that clinical information of their patients can be shared among them, as shown in Figure 1. Assuming each healthcare provider is running its own CDR, organizing the CDRs as a single federation can achieve the goal, without necessitating the consolidation of all clinical data at a single CDR, say t
42、he regional centre. When a patient visits any of the member care providers, all clinical documents can be retrieved through a single federated query with the consent of the patient. In this use case, IHE XCA may be used. ISO 2012 All rights reserved 3 ISO/TR 13128:2012(E) Figure 1 Use case of clinic
43、al document sharing via regional federation without replication 7.2 Clinical document sharing via regional federation with replication In this use case, the setting is similar to the previous one: healthcare providers located in a specific region form a federation to share the clinical information o
44、f their patients. Primary care providers usually cannot afford expensive facilities to protect their patient records as secondary or tertiary hospitals do. If unforeseen disastrous events (such as fire, earthquake, flood, etc.) occur, the whole or part of their data can be lost. Also, the primary ca
45、re providers very often keep their computers on only during their office hours, beyond which patient records are not available to other care providers, for instance, the emergency room at a tertiary hospital. If the contents of the CDRs of primary care providers are replicated somewhere else, say a
46、regional centre, as shown in Figure 2, the data can be both protected in the presence of disasters and available even after their office hours, because tertiary or secondary hospitals tend to have better computing facilities that are operational on 7-24 basis. In this use, IHE XCA can be used for no
47、n-federated queries and might be used for federated queries as well (to be further analysed). 4 ISO 2012 All rights reserved ISO/TR 13128:2012(E) Figure 2 Use case of clinical document sharing via regional federation with replication 7.3 National federation of hospitals for research purposes with re
48、plication Suppose a government is planning to set up a network of hospitals with repositories of human-originated specimens such as tissue or blood samples. Each hospital acts as a regional centre and maintains a CDR for CDA documents containing information about the specimen they store. The governm
49、ent wishes to maintain copies of the CDRs of the hospitals, as well as its own CDR for specimens sampled at government-sponsored institutions, as shown in Figure 3. The primary purpose of the network is to provide nation-wide specimen information to researchers so that they can search and ask for allocations of the specimens of interests for their experiments. A key recommendation is that the whole network of the CDRs should be seen as a single unified CDR so that anyone can cast a query to any of the hospitals and the government and still get
