Implementation of Web Services Based Electronic

Medical Record

Kevin W. McEnery, M.D.Charles T. Suitor, M.S.

U.T. M. D. Anderson Cancer CenterHouston, TX

Web Services EMR Why web services

Advantages over traditional EMR Review implementation

Current status Discuss technical details

Security, scalability National Health Information

Infrastructure and WS Questions

EMR Project overview

Legacy systems were on a variety of platforms No single access method could

retrieve all the data we needed. The technical solution had to be

affordable, and we had to be able to implement it quickly.

Traditional EMR Model Limitations

Institutional Data Model may not easily map into EMR vendor’s data model Legacy systems have an inherent data structure EMR have their own data structure These may be incompatible

EMR application workflow does not easily mesh with institution’s workflow EMR application customization$$$$$$ Institutional training session$$$$$ Long project delay$$$$ Numerous failure example$$$$$$$

Institution’s strategic decision

Departmental systems best meet the needs of the business unit

System selection not biased toward EMR Radiology – Siemens RIS, Stentor PACS Pathology – Tamtron Laboratory – Cerner Operating room – PICIS Pharmacy – GE BDM

Web Services Enterprise EMR

implementation? Scalability? Security? Institutional support

requirements?

“I ask Congress to move forward on a comprehensive health care agenda… improved information technology to prevent medical errors and needless costs…”

George W. Bush, State of the Union, 2005

Each folder is web service Allergies Reports

Radiology Laboratory Pathology

Images Pharmacy Cardiology OR Schedule Clinic Schedule Hospital Census

Radiology Information

System

Conventional System Architecture

“Monolithic Application”

RIS Application

Pathology Information

System

Pre-OP RecordsSystem

Scanned Documents

Pharmacy System

Hospital Information

System

PACSEchocardiologySystem

TranscribedDocument

System

`

Radiology Information

System

Laborartory Information

System

VitalSigns

Central Data Repository

EMR Application

“Traditional EMR” “Monolithic Application”

Web Services Implementation

Multiple clinical data sources already existed Level of enterprise availability varies

e.g. Pharmacy system allergy data Legacy systems address needs of owners

“Best of breed sub-systems” RIS, LIS, anatomic pathology…

Single vendor solution unlikely Single legacy system contains official result

Radiology report in RIS Path reports in pathology system

XML

ClinicStationClinicStation

`

Pathology Information

System

Pre-OP RecordsSystem

Scanned Documents

Pharmacy System

Hospital Information

System

PACSEchocardiologySystem

TranscribedDocument

System

Radiology Information

System

Laborartory Information

System

VitalSigns

Clinical Data Repository“Clinical Source Documents”

Legacy System Database Stores Clinical Data

Clinical documentationentered directly into legacy system by clinician

Automatically availablethroughout the enterprise

Application Tier

Client Tier

Web Services Architecture

Network

Network

Pathology Information

System

Pre-OP RecordsSystem

Scanned Documents

Pharmacy System

PACSEchocardiologySystem

Radiology Information

System

VitalSigns

Hospital Information

System

TranscribedDocument

System

Laborartory Information

System

Clinical Data Repository“Clinical Source Documents”

Clinical Documentation

Patient Interaction

Dictate Note

Edit note

Sign note

Patient Interaction

Dictate Note

Edit note

Sign note

Patient Interaction

Dictate Note

Edit note

Sign note

Review Last Interaction Review Last Interaction

Limitations of “traditional” clinical data

Much clinical data non-structured Dictated clinical notes Handwritten clinical notes Medical images

Limited information regarding image content No current accepted, or legislated,

standard regarding structured clinical data Exception: Pathology, Mammography

Limited capability to automatically share clinical data across enterprise

Standardization of clinical data

Recorded at the appropriate level of detail

Consistent over time and across boundaries

Transmitted without loss of meaning Aggregated at more general levels and

along multiple different perspectives Interpreted by automated systems

Modified from SNOMED Overview – American College of Pathologists

Allergy

Medications Listing

Review of Systems

Height Weight - Vital Signs

MRI Checklist

Surgical History

MRI Experience

Signature and Authentication

Patient Demographics

DI Exam Patient Checklist Data

Pain Symptoms – Vital Signs

Diabetic History

Pregnancy -Breast Feeding

Patient Demographics

Height Weight

Vital Signs

Review of Systems

Allergy

Redundant Clinical Information

Allergies Family History Medical/Oncology History Surgical History Current Medications ROS Patient problem list

Trend – Structured Documents

XMLXML

Store DataStore Document

AllergyWeb Service

Review of SystemsWeb Service

Medication

Web Service

Clinical Web Services Allergies Family History Medical/Oncology History Surgical History Current Medications ROS Patient problem list

Redundant Clinical Information

Web services: Beyond EMR Patient Schedule

ClinicStation myMDAnderson.org Patient kiosks Electronic whiteboards

Diagnostic Imaging (8) Emergency Center

Web Services: Unlocking data

Radiology Information

System

RIS Application

RadiologyReports WS

DI Patient Tracking WS

ProcedureComments WS

Patient Schedule WS

Emergency Center Web Services

ER ActivityDigital Whiteboard(viewable in ICU)

ER Room CensusDigital Whiteboard

DataSource

XML-based web service

Rules Tier

Client Tier

XML

XSL

HTTP

Web Services: XML data

Distributed clinical architecture

Services-based architecture provide a standard method to access and update clinical data Numerous applications possible

Structured data flows to client XML

Client formats and interacts with data for display

Structured data flows to server XML

Will it scale?

Instant access to clinical information >100 transactions/second >1,200,000 patient queries per month

>50M audit event per month

6,197 computers 52.2 million

transactions/month

5,753 users 1,073 physician users

Web Services Architectures

Multiple Web Services # Web Services = # Functions

Single Web Service 1 Web Service Many Functions

Building Web Services

Clients call functions via a web server

Examples GetRadiologyReport(Accession)

GetLabProcedures(MRN)

Building Web Services

Each Web Service must have several features Security Auditing Maintainability Specific business logic

Building Web Services Solve the common problems

once Provide a single Web Service that provides

Security – most likely a session Auditing – in and out available Dispatching to work components

Building Web Services Individual functions can be

components (i.e. GetRadReport) Business logic only, no security or

auditing Each function/component can be

independently updated and monitored

Monitoring Components

Characteristics of Components

Stateless Especially important for server farms

Short execution time Keeps simultaneous execution down

Characteristics of Components

Single Function per Component Easier to maintain & update

Designed for multiple instances executing simultaneously Proper threading model No shared resources

MDACC Server Configuration

10 server farm, load distributed, via hardware network load balancer

Each server is dual processor, 2GB RAM, Win2K Server Commodity pricing Robust performance

MDACC Performance Data collected every 5 seconds

over a 24 hour period

Executing

Req/sec

CPU % Connections

Average 14 35.3 2.45 903

Max 149 162.2 18.8 2778

Min 1 4.0 0.08 29

Web Services Web Services aren’t magic Web Services systems only scale

if they are designed to scale We have encountered a commercial

Web Services HIT system with limited throughput

10 simultaneous queries, 3 sec/query

Integration

Capabilities of legacy systems need to be considered

Underpowered systems can be protected with a cache Query based cache HL7 replication based cache

Web Services EMR Web-services can provide a

method for universal access to clinical information already available in legacy systems Alternative to centralized archive Best of breed legacy sub-

systems

Web Services Enterprise implementation?

Yes and growing… Can it scale?

1.2M patient queries/month Are they secure?

Yes and meet HIPAA audit requirements What are institutional support

requirements? Minimal day to day Leverage existing institutional

investment

Discussion…

kmcenery@mdanderson.orgcsuitor@mdanderson.org