I have been too pre-occupied with my work to do some quality blogging; I have not written anything till now about my favorite topic – Electronic Health Records. This is first of serious of blogs on various EHR initiatives around the world.Most of the information that will be included is public information and my intention is to simplify the information about the implementation from what i understand while allowing the users also to examine the contrast in the patterns used by different implementations. I have been told that Brazil is one of the first countries to have a successful implementation of Nation Wide Electronic Health Records. The project was termed NHCP – National Health Card Project. This project began as early as 1999 and a clinical pilot began in 2001
Aim of NHCP
The project was started to create national patient identification and information system for the Brazilian Unique Healthcare System called SUS -- Sistema Único de Saúde. Its aim is to collect patient treatment information in a national repository of clinical data.
Architecture Principles and Components
Figure below shows the logical architecture of the project. NHCP System is divided into 5 hierarchical levels, from the bottom: Point of Care Level, Municipal Level, Concentrator Level, State Level and Federal Level. The top three levels of the system has Permanent IP based network and the lower two levels has Dial Up Network as shown in Figure below.
NHCP Project has five major components
Ø Telecommunication infrastructure
Ø Point of care terminals;
Ø Servers and database facilities
Ø Point of care terminal and servers software
Ø Security issues and national standards to represent transmit and store health information.
The architecture of the NHCP is centered on patient and users having health cards. The health cards adopted in the project are used only for IDENTIFICATION purposes of users and health professionals and not to store clinical data. Both the users’ and health professionals’ cards have embossed the unique identification number, name, date, city and state of residence. The point of care equipment specially developed for this project has the card reader. The access to the system is limited to health professionals authenticated by the card and password. All data captured at the point of care is stored in the servers at the municipal, state and federal level
The technologies that were used are based on Java technology and the XML data format. The Java framework is based on the following concepts
Ø The NHCP is XML message-based; all communication between machines is XML over HTTP.
Ø Every server node can send and receive XML messages to and from any another server node.
Ø XML messages are associated to Java business classes.
Ø All XML data is handled dynamically using Java Reflection.
All XML is validated according to a rigid specification (DTD, infrastructure, and domain), which provides the flexibility necessary to add or remove business classes, and to modify the XML validation rules. In addition, servers and clients must authenticate to a server node using digital certification. The figure below depicts a generic server node with its principal building blocks and data flows.
Standards and Data Sets
The transport protocol used is HTTPS (HTTP +SSL). The terminals of care and municipal servers communicate using XML. The specifications were not HL7 but specifications agreed between Ministry of Health and the providers contracted for the development of the project. Document Type Definition (DTD) has been used for specifications.
The essential encounter data set contains the following information
Ø Reason for the encounter
Ø Diagnosis
Ø Procedures Performed
Ø Patient’s work-out
Ø Medication
Ø Follow Up
The diagnosis information is entered using ICD-10
Informational Governance
For authentication any addition or alteration of information in the system is linked to an operator duly registered both for operation of the server and the terminal. All the health professionals responsible for the entry of data to the system are authenticated using health professional card which contains a encrypted password on the card.For access control, the system allows the implementation of a policy of setting privileges of access to classes of operators and standards of disclosure. All attempts to access information and functions of the system are stored for auditing purposes.
From IG point of view the systems offline are treated the same way as that of online systems. The traffic between a terminal and a server, upload between servers or service is performed on the HTTPS protocol, or HTTP protocol (Hypertext Transfer Protocol) protocol on the SSL (Secure Sockets Layer).
Scalability
Since spring 2003, the pilot infrastructure has been fully operational, consisting of:
Ø 8 million patient ID health cards
Ø 50,000 professional ID cards
Ø 3200 point-of care-clients
Ø 2 federal servers
Ø 27 state servers
Ø 13 concentrator servers
Ø 44 municipal servers
In parallel with the pilot project and in anticipation of consolidation for the rest of the country, 80 million people have been uniquely identified in the NHCP database, representing 40% of the Brazilian population. Interoperability with external systems is also operational. Systems from external vendors are communicating with the NHCP by exchanging XML documents.
NHCP server -side data:
Ø 180 different use-cases
Ø 1,800 Java classes
Ø 230,000 lines of code
Ø 700 different database tables
Ø 160 different XML message types
Ø 50 gigabytes of data/million users/year
Advantages
NHCP allows data to be queries and profiled; for example diagram below shows actual data queried from the NHCP system for San Jose dos Campos, a city of 500,000 people near Sao Paulo. The x axis shows the treatment procedures codes, the y axis the date, and the vertical z axis shows the corresponding quantity. So what happened to cause this peak? From the data, it was possible to identify that the peak was due to the annual influenza immunization program; it was in winter, and over a two-week period, nearly 5000 people got their influenza shots.
The project is simple implementation but strictly not a EHR implementation per-se and looks more of a data ware house implementation. There were claims that the message specifications were done after debate with clinicans who were the main users. It did not follow any reference model based specs so any of the changes to the specifications to keep in line with advances with clinical terminology and data will be adhoc. Also usage of ICD10 will limit the amount of data collected considering that its mostly disease based. The data sets indicate minimal information is captured and also a mechanism to retrieve from central repository to point of care systems is not well defined. The integration mechanism looks like a hardcore java implementation and non-implementation of a standard middle ware implementation will have its own technological refresh problems and scalability problems. Also some of the technologies used like DTD , XML binding has since become rarely used with the advent of XSD , SOAP , JAXB etc as the artcile on the SUN website indicates.
Links, References, Acknowledgements and Copyright
http://java.sun.com/developer/technicalArticles/xml/brazil/
