The path to the all-digital healthcare enterprise is strewn with integration hurdles that continue to challenge organizations striving to implement images and information across departments, from admission and registration to treatment and discharge. Incompatibilities between competing vendor's systems have forced hospitals to employ numerous software interfaces - including XML, service-oriented architecture and web services - to allow caregivers across the facility to access, review and update patient data.
For the past several years, the radiology information system (RIS) has been able to exchange patient data with the hospital information system (HIS). This includes admission, discharge and transfer (ADT) orders and other patient information stored in HL7 format in the HIS. More recently, healthcare organizations have been combining DICOM-format images and modality work lists stored in a picture archiving and communication system (PACS) with HL7 data in the RIS and HIS. This has been made possible by development of application programming interfaces (APIs), brokers, or intermediary data repositories where the HL7 to DICOM translation happens. Another method is a brokerless PACS, which can translate HL7 data to DICOM format and vice versa, allowing information to be seamlessly transferred from a HIS without additional software or hardware.
Cross-vendor compatibility initiatives such as Integrating the Healthcare Enterprise (IHE) address the problem of sharing different data types among disparate systems, but it's still no easy task to smooth the flow of patient data throughout the hospital. One clear benefit of the development of a standards framework like IHE is that it allows hospitals to implement products, including the HIS, RIS and PACS, from multiple vendors. Healthcare organizations of all sizes benefit from cross-vendor compatibility, but especially those with sprawling IT infrastructures, where IT and clinical departmental managers prefer to mix-and-match systems.
"There is no single vendor that has a system that will satisfy everyone," says Nogah Haramati, MD, chief of radiology at Montefiore Medical Center in New York, N.Y, and professor of clinical radiology and surgery at the Albert Einstein College of Medicine. The 1,062-bed organization has a LastWord HIS and Imagecast RIS from IDX Systems Corp. The RIS is connected to GE Healthcare's Centricity PACS. According to Haramati, IHE has taken the burden of developing software interfaces off of users and vendors.
"PACS and RIS vendors used to have to do secret, intensive work to create custom interfaces between systems," he says. "IHE is designed to solve the interface problems using existing standards, and rigidly specifying every transaction. The fundamental change is that IHE doesn't care how you define the system. Each vendor, whether it's the 800-pound gorilla or a start-up in a garage, can build its side of the technology. In every area, IHE will decide the critical discrete functions for image archiving, image display, or system rescheduling," he says.
"We learned that one size doesn't necessarily fit all," says Paul Chang, MD, director of radiology informatics at the University of Pittsburgh Medical Center in Pittsburgh, Pa. Chang, also professor of diagnostic radiology at the University of Pittsburgh School of Medicine and medical director of the Enterprise Middleware Group, is responsible for ensuring that all departments can share data across disparate systems across 19 hospitals with a combined 4,000 beds.
"Users should not have to compromise on product selection," Chang says. "Not just radiology, but all departments. I'm giving up too much if I give up best-of-breed."
Of course, when an organization implements PACS in addition to a RIS and other departmental systems, HL7 and DICOM data needs to be translated and shared by the two systems. But across the enterprise as a whole, those data formats are only a small part.
"Here, HL7 and DICOM are edge protocols, and simply asking specifically about integrating the HIS, RIS and PACS is asking the wrong question. That's more of a narrow, radiology perspective," says Chang, whose enterprise middleware group has developed a service-oriented architecture that uses Extensible Markup Language (XML) objects to exchange data between a Cerner Corp. HIS, Stentor Inc.'s iSite PACS (which Chang helped develop), and other web service-enabled systems.
Whatever the integration method - from brokers to custom APIs