VistA HL7 ADT Filer

Is it possible to implement CPRS without also using VistA for patient registration and ADT? The answer is YES. Another computer system that supports HL7 messaging may be used to register patients. Essential patient data such as demographic information, admissions and discharges may then be transferred to VistA via HL7, enabling the patient to be viewed in CPRS.

The VistA HL7 ADT Filer uses VistA's HL7 infrastructure along with additional programs and files to receive and interpret incoming ADT data from another computer system (see diagram). The filer may be customized to deal with virtually any type of HL7 message or segment as it uses dynamically configurable mappings to interpret and file incoming data to appropriate VistA database locations.

Patient movement processing in VistA includes more than just filing data. For example, it may be necessary to notify other applications when an important change in patient status occurs. For this reason, the VistA HL7 ADT filer simulates selected aspects of the internal VistA patient movement processor.

Some VistA data files and fields are carefully controlled, for example provider identifiers or ward locations or formulary entries, etc. These data elements belong to VistA master files and should not be changed without due care. The VistA ADT Filer is aware of these restrictions and honors them.

Ordinary data elements, such as a patient's street address are handled through simple-to-define and easily modified mappings. Each mapping is associated with a specific event driver protocol (associated with a given HL7 message structure). Within a protocol, data elements (fields, components and sub-components) may be processed in any assigned order. The Filer can “remember” where data are being filed so that related elements may be easily directed to the same or associated locations.

In the example shown above an HL7 component PID.11.1 (patient identification segment, sequence 11 patient address, component 1 street address) is mapped to the VistA patient file, field .111 (street address line 1). Before being filed the value is transformed to uppercase (VistA convention). The ADT-A28 event driver is the governing protocol. No filing order is specified for this example field. However, other fields in the same message structure may have been specified to file before or after the example one, by including negative or positive filing orders in their definitions.

For additional information about the VistA HL7 ADT filer please contact us.