to JapaneseDocument

1. What is the MML?

The MML is the specification foroptimum exchange of clinical data between different clinicalinstitutions. The database can be considered to be a kind of table.Each institution uses a uniquely defined table. Therefore, theexchange of a simple data set such as that includes address, name,diagnosis, etc. may lead to different sequence of data betweeninstitutions. If such data is transmitted as is, the data sequencechanges. To allow for proper exchange, the database for all clinicalsystems should be integrated into the same structure. However this isimpractical as all systems currently operating throughout the countryworld have to be rewritten. The MML (MedicalMarkup Language) is a standardformat for data exchange which we have studied for the purpose above.The latest version MML has been developed via XML technology. Toensure that the specification is available for multiple electronicmedical chart systems, the data is converted into MML documents (MMLinstances) for data exchange with other institutions. (Fig. 1) Theinstitution receiving the data converts the MML data into its ownformat for mapping to the database. This allows for the data exchangefor clinical institutions throughout the country while maintainingthe uniqueness of each institution. Each system is designed by eachvendor on a competitive basis. The principle of competition will leadto the development of a better system of operation.

Another advantage of using MML isthat each system only has to prepare one interface for the standardformat. (Fig. 2) If a different interface for data exchange betweendifferent systems had to be prepared, the number of interfaces wouldbe numerous. It would be impossible to prepare such a number ofinterfaces.

Fig. 2 When exchanging databetween databases with different structures,
each institution only has to have one interface for the standardformat available.

The MML idea was first born at theSeagaia Meeting (Annual Meeting of The Japan Association for MedicalInformatics "Electronic Health Record Research Group") held inMiyazaki in May, 1995. At that time, the method using SGML wasreviewed. The data exchange method with the SGML (StandardGeneralized Markup Language) was taken over by the Research Group(consisting of members from the Electronic Health Record ResearchGroup) of the Electronic Medical Chart Development Project of theMinistry of Health and Welfare which started in 1996. Currently, anMML working group from the Electronic Health Record Research Group iscarrying out ongoing development of the method.

MML uses a description method similar to thatof HTML (Hyper Text Markup Language) for the creation of Internet webpages. In general, this kind of description method is called a"markup language". HTML tags contain information such as<center>, <H1>, <p> (centering, header 1,paragraph, respectively) for layout of characters. It is easy to sendclinical information in HTML format. However layout of the data mustbe acceptable to the end user visually.

If the following HTML information

<left>JamesBond</left><p>
<left>Gastriccancer</left><p>

is sent to another institution, the data is displayed with leftaligned as shown below.

James Bond
Gastric cancer

This information is easily recognizable by human as name anddiagnosis. In order to be recognized by a computer and to map thediagnosis and the name in a database, for processing purposes, it isbetter to use tags with medical terms like:

<name>JamesBond</name>
<diagnosis>Gastriccancer</diagnosis>

The technology for transmission of medical information with tags like<name> or <diagnosis> in the example above is the MML. Wehave reviewed the logical structure of the medical chart and detailedthe medical categories (diagnosis, symptom, etc.) used in the charts.We then defined such categories as tags with a medical meaning. Withthese tags, the DTD (Document Type Definition) may be formed usingthe SGML. The DTD is a definition format for the SGML documentstructure or tags. The MML is equivalent to the DTD of the SGML. Whenthe data is exchanged between medical facilities, medical informationcan be properly sent if converted into an MML document (the SGMLdocument in a broad sense). From version 2.2.1, the MML is describedin the XML (eXtensible Markup Language) format which is a languagedeveloped from the SGML. Considering that medical information ismainly exchanged between databases, XML technology, which iswell-suited to databases, is employed. The current tendency worldwide is the use of XML as a standard technology for data exchange. Weare proud that we have taken the logical choice.

2. MML latest version

The latest version 2.2.1 is basedon previous versions using SGML. SGML has now completely changed toXML. Changes from the previous versions are as follows:

MML Part 1

1) The structure was separated (into modules)with NameSpaces. This has allowed development of individual modulesfor each medical department. In upgrading to a newer version, theeffect on the entire program has been minimized.

- Modules for repeated structures
- Modules of sections that can be separated for terminology

2) Addition of surgery record module
3) Details of clinical summary module

MML Part 2

We have defined the draft related tothe electronic message including search, addition and deletion.
With the above changes, the MML is separated into the frame structure(white block) and the modules (blue block) used in the structure asshown below. In actual operation, modules (sub DTD) are used asnecessary. The MML is responsible for the range of modules, up to andincluding those defined here. Other functions may be added in thefuture according to requests from users.

Fig. 3 Basic structure of MML2.2.1

3. What doesMML do?

MML has been prepared as thespecification for exchange of clinical information. With MML, thefollowing applications are available.

3.1 Medicaldata exchange between different systems

It is not an easy task to exchangedata for electronic medical charts that have different databasestructures. Usually, a compatible interface is prepared for thespecified counterpart. However, this interface is not useful for dataexchange with other medical institutions. When each system hasinstalled the MML interface and then sends information in the MMLformat, the MML interface analyzes this data and stores the data intothe particular database. Then, medical staff can refer to the datafrom their own electronic medical chart system that the staff hasbeen accustomed to.

3.2 Databackup in the facility (electronic medical chart for long-termstorage)

The electronic medical chart systemstores large quantities of data such as order information, medicalinformation, etc. In addition to the clinical data, it includesvarious data (flags, history records, etc.) for operation. Theinformation is not limited to clinical data only. As a result, it isdifficult to store the data for a long period time. Therefore, thedata is separated into two categories: active data, such asreservation information that may be changed, and fixed data that doesnot have to be changed. The fixed data is described in the MML formatand is stored in a separate database.

This allows efficient long-term storage ofclinical data. (Fig. 4) This is very useful if the system vendorchanges in the future. When the MML interface is installed on a newvendor's system, the clinical data can be described on the newelectronic medical chart system from the long-term database. MiyazakiMedical College is scheduled to operate this long-term storagemedical database in the year 2000. This database has an MMLinterface; it is not necessary to develop a special method for dataexchange with other systems.

Fig. 4 When the clinicalinformation is separated into real-time data and
long-term data, reasonable and efficient control is possible.

3.3 Commondatabase for local medical institutions

Ideal practice would be that eachmedical institution in the local area would install the MML interfaceon the medical chart system for data exchange. Problems still exist;inadequate internet infrastructure, economical problems for continuedaccess, and difficulty of maintaining a fully-fledged electronicmedical chart system for a small clinical facility. In fact, it isdifficult for each institution to install the MML. Therefore, themedical institutions in the local area will collectively prepare theMML-compliant database for common use. Each medical institutionshould send the MML document to this database. In this way, themedical institutions and patients who have memberships can share thedata. The system at each medical institution may be different, buteach system must install the MML interface. Private generalpractitioners or patients who do not have a special medical chartsystem can gain access to the WWW interface on the common databasevia a normal PC and see medical charts via a WWW browser.

This experiment started in 1998 in Miyazakiprefecture. 9 medical institutions including 3 prefectural hospitals,the university hospital and clinics have already gained access to thedatabase. These medical institutions are interconnected via the VPN(Virtual Private Network) for exchange of information in a safeenvironment.

Fig. 5 Common database for localmedical institutions

3.4 Remotebackup and certification of authenticity clinical data

The method described in theprevious section also functions as a remote backup of important datafor medical institutions. When the common database is managed by areliable third-party institution, authenticity of clinical data(legal proof that the data has not been altered) can be certified.Such legal proof is, therefore, convincing enough at this time. Inthe near future, a "medical data bank" that trades medicalinformation, not just a provider, may appear on the market.

4. Referenceinformation: for further reading

1) MML 2.2.1Standard

http://www.seagaia.org/MML_E1028.pdf

2) Seagaia Meeting homepage (latestMML information, Japanese-written page)

http://www.seagaia.org/

3) MML contact address

E-mail: sg-office@seagaia.org

4) Seagaia Mailing list: seagaia-ml@seagaia.org

Electronic medical chartresearch group/The Seagaia Meeting is managing the mailing list forpopularization of the electronic medical chart and furtherinformation. Anyone can join this main list. If you are interested,please register your address.
Contact for mailing list registration: sg-office@seagaia.org

5) Past materials for MMLdevelopment

Report of ElectronicMedical Chart Development Structure Technology Core Team of theMinistry of Health and Welfare/ April 12, 1996 (Japanese-writtendocument)
http://www.miyazaki-med.ac.jp/medinfo/SGmeeting/document/health/health_00.html

MML ver. 1.0 _3 (Electronic HealthRecord Research Group, Japan Association for Medical Informatics,Japanese-written document), 1997
http://www.miyazaki-med.ac.jp/medinfo/SGmeeting/document/SG97/02Ohe/ohe.html

Standardization of ExchangeProcedures of Clinical Information, and an Experiment of ClinicalData Exchange Using Medical Markup Language (MML), JJMI; 17(Suppl.):203-207, 1997
http://www.miyazaki-med.ac.jp/jjmi/17_3s/17_3s_05.html

Medical Markup Language (MML) - An SGML DTD for Medical RecordsInformation, 1998
http://www.miyazaki-med.ac.jp/199805MMLFrance/

MML Version 2.0 (MML Working Group, Electronic Health Record ResearchGroup, Japan Association for Medical Informatics, Japanese-writtendocument), 1999
http://www.miyazaki-med.ac.jp/medinfo/SGmeeting/SGmeeting99/doc/MMLV2/MML_v2.html

MML 2.0 Standard (Japanese-writtendocument), 1999
http://www.miyazaki-med.ac.jp/mmlv2/index.htm

Epilogue

The above provides a generaldescription of MML. Hopefully, the XML technology represented by MMLwill become ever more popular and that adequate medical services willbe provided to all patients. (Written by: Hiroyuki Yoshihara, MML-WG,Electronic Health Record Research Group, Nov. 15, 1999)