Standardized electronic transfer of blood product information

Secure transfer of information on product identification and characteristics is essential for the safe clinical application of medical products of human origin (MPHO), including blood for transfusion and cells and tissues for transplantation. Standardized information provides clarity and avoids ambiguity, and standardized encoding of this information permits the use of automated data transfer systems, thus avoiding the risks associated with manual transcription errors. The ISBT 128 international information standard supports this objective, and the ISBT 128 Standard has been widely adopted. Designed originally as a labeling standard, ISBT 128 traditionally transfers information via bar codes on the product label. Demand for increases in both the quantity and accessibility of standardized information is growing. ICCBBA has responded by developing a new standard ¹ that allows ISBT 128 information to be transmitted in electronic messages in a manner that is compatible with its existing standards. This development will facilitate the introduction of electronic dispatch messages that are able to provide a full range of ISBT 128 information and support one‐off lookups for a specific product for hemovigilance purposes.

The first successful effort to achieve a degree of information standardization in blood transfusion occurred with the development of the ABC Codabar bar‐coding standard in 1975, which was used by blood transfusion services in several countries. This standard operated successfully for a number of years, but by the early 1990s, divergence in the functional development of the standard and a lack of flexibility to accommodate new developments in transfusion medicine became limiting factors. ²

The ISBT 128 Standard was developed as a replacement for ABC Codabar, with the first version of the standard being published in 1994. ³ Supported by an organization dedicated to its maintenance and development, ISBT 128 has grown both in the range of products that use the standard, now encompassing all MPHO, and the amount of information that can be transferred. ⁴ , ⁵

Information encoded in ISBT 128 was designed to be transferred using linear bar codes. Blood centers encode the information into bar codes that are printed on the product labels, and receiving hospitals scan the codes and interpret the information in accordance with the ISBT 128 Standard. Although highly effective and secure, this approach does have some limitations. In particular, the amount of information that can be encoded on the label depends on the amount of label space available to accommodate bar codes, and the information transfer depends upon the physical presence of the product label, thus limiting the point in time at which information transfer can occur. The former limitation can be addressed to some extent by the move toward two‐dimensional symbols (Data Matrix), which can hold a much greater amount of information in the available space, but this does not solve the problem for very small containers.

Electronic messaging is widely used in healthcare applications, with standards such as HL7 providing comprehensive standardized healthcare messages. These standards allow organizations to transfer a wide range of information in a structured manner. Messaging standards standardize how the message is structured, transferred, and acknowledged but do not define the data content for specialist areas of medical information. Instead, they support the embedding of data encoded using approved data content standards within the message. For example, HL7 provides two messages widely used for laboratory test results, the Observation Request Segment and the Observation Result Segment. Within these segments, an actual test may be identified using a code specified using the Logical Observation Identifiers Names and Codes (LOINC) standard.

Recognizing the benefits of electronic messages and their ability to overcome the limitations of bar codes indicated above, ICCBBA has developed a standardized electronic message representation for information about MPHO. Electronic message segments that organize the information in a standard format and utilize existing ISBT 128 data elements and reference tables have been defined. Such segments can be incorporated into a variety of messaging standards and electronic delivery systems, thus providing flexibility on a global basis. Such an approach preserves existing ISBT 128 standard terminology and reference tables and ensures consistency between the information provided in electronic messages and the information encoded in the bar codes on the label.

In ISBT 128, data structures carry information organized in a manner that provides the best efficiency of linear barcode usage. This means that, in some cases, a data structure may contain more than one piece of information, and in other cases, one piece of information may appear in more than one data structure.

For example:

• Data Structure 018 contains a single data element, the container lot number;

• Data Structure 001 contains two data elements, the donation identification number and the flag characters; and

• the division number of a product may appear in Data Structure 003 or in Data Structure 032.

The need to reorganize the presentation of information as discrete data elements was recognized. Each Data Element used in the electronic message was assigned a Uniform Resource Locator (URL) as a Uniform Resource Identifier (URI) to permit its globally unique characterization, and web pages were developed to resolve these URLs and provide information on the data element (see www.isbt128.org/uri). A mapping was developed to link the data present in ISBT 128 Data Structures and the Data Elements of the electronic message.

The list of data elements at the time of publication is shown in Table 1, and an extract of the mapping is shown in Table 2. These tables are updated at regular intervals, and the current versions are accessible from the ICCBBA website.

TABLE 1.

List of data elements (see ref table RT‐042 on ICCBBA website for full descriptions)

Data element	Extensible Markup Language tag
REQUIRED
Medical products of human origin unique identifier	MPHOUniqueIdentifier
Donation number	DonationIdentificationNumber
Product type	ProductDescriptionCode
Division identifier	DivisionIdentifier
OPTIONAL
Flag value	FlagCharacters
Collection date and time ISO	CollectionDateTime
ABO RhD	ABORhD
Collection type	CollectionType
Production date and time ISO	ProductionDateTime
Expiration date and time ISO	ExpirationDateTime
Container manufacturer	ContainerManufacturerID
Container catalog number	ContainerCatalogNo
Container lot	ContainerLotNo
Processing facility identification number	ProcessorFIN
Facility product code	FacilityProductCode
Single European code	SingleEuropeanCode
Global registration identifier for donors	GRID
Infectious marker	TTIResults
Red cell antigens with test history, individual	RedCellAntigen
Special testing general	SpecialTestCode
Platelet HLA and antigen	PlateletHLAandAg
Dimensions, single	Dimension

Abbreviation: ISO, International Standards Organization.

TABLE 2.

Extract of mapping from data structure to data element (full table available from ICCBBA website)

Data structure	DataStructure data	Data element	Extensible Markup Language (XML) map	XML data
1	A99992012345601	DIN	DonationIdentificationNumber	A999920123456
		Flags	FlagCharacters	01
2	62S0	ABO/Rh	ABORhD	62
		Rh K Mia/Mur	RedCellAntigen	0060010106
3	E4306VA0	PDC	ProductDescriptionCode	E4306
		Collection type	CollectionType	V
		Divisions	DivisionIdentifier	A0

Message segments are based on Extensible Markup Language (XML) using the World Wide Web Consortium (W3C) Recommendation. ⁶ This markup language was developed in 1988 to provide a standard method to carry data. It is an extensible language, which means that if new data elements are added in the future, XML applications should continue to work, although they may not be able to process the new data without modification. XML is widely used in healthcare applications. While JavaScript Object Notation (JSON) is replacing XML in many areas, the namespace support of XML permits the use of a schema to control the semantics and permit message validation.

An XML Schema Definition (XSD) is provided for each standard XML message segment, thus allowing messages to be validated against the standard. The XSD provides an approved structure, identifying the subelements that may occur in the element, the order of appearance, the cardinality, and some format verification. The schema also verifies that the URI in the identifier attribute is the correct one for the XML tag.

ISBT 128 XML elements are defined as stand‐alone elements that can be incorporated into a variety of messages. Each standardized ISBT 128 XML element is a complex type designed to support the communication of a specific dataset. XML elements nested in this parent element are identified using a specified XML tag and with attributes of identifier and value.

Take as an example the Donation Identification Number data element, which is represented by the first 13 characters of the DIN Data Structure. The specified XML tag for this data element is DonationIdentificationNumber, and its URI is represented by the URL https://www.isbt128.org/uri/DonationIdentificationNumber . To transmit a donation identification number of A999920123456, the XML subelement is:

<DonationIdentificationNumber Identifier = “http://www.isbt128.org/uri/DonationIdentificationNumber“ value = “A999920123456”/>.

Similarly, for an ISBT Product Description Code of E0001, the XML subelement is:

<ProductDescriptionCode Identifier = “https://www.isbt128.org/uri/ProductDescriptionCode“ value = “E0001”/>.

The above describes the general approach to developing ISBT 128 XML message segments and the mechanism for creating each subelement. The first such ISBT 128 XML Message Segment has also been specified: the MPHO Product XML Element.

The MPHO Product XML Element provides the dataset associated with a single MPHO product for transfer from the processor to a healthcare organization (e.g., from blood center to hospital transfusion laboratory). It incorporates all the information traditionally carried in bar codes on the product label together with the opportunity to include further product specific information.

Only basic identification information is mandatory in an MPHO Product XML Element; all other information is optional, and its inclusion is at the discretion of the message provider (blood center). Not all elements are applicable to all MPHO types.

An example of an MPHO Product XML Element for a blood unit is shown in Figure 1. The information contained in this message, when interpreted using standard ISBT 128 reference tables, is as follows:

FIGURE 1.

Medical products of human origin product element example [Color figure can be viewed at wileyonlinelibrary.com]

Donation Identification Number: A999920123456

Product Description Code: E0398 (RED BLOOD CELLS, CPD > AS5, 450 ml, refg, Irradiated, Res Leu < 5 × 10⁶)

ABO/RhD: A RhD Positive

Collection Date: Mar 2, 2020

Expiration Date: Apr 6, 2020

Donation Type: Volunteer

Blood Container Manufacturer Code: IC

Blood Container Catalog Number: 27QZE

Blood Container Lot No: 123456

Processing Facility Identification Number: A9999

HIV PCR Negative

HCV PCR Negative

HBV PCR Negative

Syphilis Ab Negative

CMV Ab Negative

WNV PCR Negative

Rh C Positive: Tested ≥ twice on different collections (historic only) with concordant results

Rh c Negative: Tested ≥ twice on different collections (historic only) with concordant results

Rh E Negative: Tested ≥ twice on different collections (historic only) with concordant results

Rh e Positive: Tested ≥ twice on different collections (historic only) with concordant results

K Negative: Tested ≥ twice on this collection only, different samples, with concordant results

Fy^a Negative: Tested once on this collection

The development of a standardized approach to incorporating ISBT 128 data elements into electronic messages is an important step in improving the communication between healthcare organizations involved in the production and clinical application of MPHO. By adopting this standard, organizations will be able to benefit from the MPHO‐specific standardized terminology and standard reference tables of ISBT 128 in a wide range of contexts and securely transfer more information about MPHO products with far greater flexibility.

The most common use of MPHO information transfer is the dispatch and receipt of blood product consignments, and the MPHO Product XML Element has been developed to support this application. One instance of an MPHO Product XML Element is used to carry information about one MPHO product, and by sending multiple instances in an electronic dispatch document, full information on a consignment can be transmitted. A simple electronic dispatch document format is shown in Figure 2.

FIGURE 2.

Simple dispatch note format

Such a dispatch document could be provided in a number of ways depending on the level of development of the information infrastructure. It could be sent as part of an electronic message or could equally be sent on physical media such as a USB flash drive.

Another scenario would support the lookup of information on individual units. A mobile phone app could, with appropriate security, scan the donation number and product codes from a unit and send an Application Programming Interface (API) request to the blood center for information on the product. The MPHO Product Element could be returned to provide comprehensive and up‐to‐date information about the unit. Such an approach may be beneficial in hemovigilance investigations.

Further message segments, based on the standardized general approach, can be developed to support other use cases (e.g., electronic orders).

The use of standardized messages may require further standardized terminology and reference tables that are not directly related to product labeling. ICCBBA is well positioned to develop such structures through its network of more than 200 volunteer subject matter experts across all areas of MPHO.

CONFLICT OF INTEREST

The authors are employed by ICCBBA.