American Association for Clinical Chemistry
Better health through laboratory medicine
NACB - Scientific Shorts
NACB - Scientific Shorts (formerly NACB Blog)
By Corinne Fantz, PhD, DABCC, FACB
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The use of bar codes for identification purposes has made many health care processes more reliable and efficient. However, while the current laboratory standard is Code 128, it is certainly not the safest and most reliable symbology in use today.  Malfunctioning bar code printers, improperly sized wristband bar codes, and less than optimal bar code orientation and width have all been shown to be sources of bar code-related, patient mis-identifications (1).

 

In contrast to linear bar code symbologies which can be encoded with only one patient identifier, newer bar code symbologies, including 2D and matrix type bar codes, may be encoded with multiple patient identifiers, and contain more sophisticated checking algorithms such as error correction.  Furthermore, because redundant data can be embedded in these more sophisticated bar codes, up to 30% of the bar code can be destroyed and still produce accurate data when scanned.  These symbologies are already in widespread use in a number of industries including banks, the pharmaceutical industry and mail delivery services. 

 

Check bar coding processes for potential sources of errors

Probably the most effective solution to check the integrity of bar codes before releasing them into the patient care environment is to use commercially available verification devices.  These devices can be used to verify the adequacy of bar codes before placing them into service.  Bar code verifiers can be a good investment, especially if the user has frequent printer failures.  If there is flexibility in the bar code printer software, bar codes should be oriented such that printer failures generate white lines perpendicular to the bars of the linear bar code, preserving the integrity of the bar code data.  Neither of these solutions will prevent post-printing wear and tear that can lead to errors over time.  Required manual checks have been made policy to detect post-printing damage, particularly in high-risk healthcare environments, such as blood bank specimen labeling, but these checks are also not full proof (2), suggesting the real need for more reliable identification technologies and/or redundant data processing.

 

Adopt strategies to improve accuracy of bar coding process

Implementation teams should seek to include representatives from all areas intending to use bar codes, to garner the needs of all the various users.  For example, groups may have very different size constraints (space on tube or wristband). The team should also become familiar with important bar code specifications, making sure that any generated bar code meets minimum bar code scanner requirements, and this is true for all scanners throughout the healthcare system.  From a technological perspective, if there is only one type of bar code in your system, the scanners should be limited to read only that bar code symbology.  Procedures to maintain and monitor printer performance and detect malfunctions are also important to prevent errors.  Are operators notified when printers are in need of maintenance?  Are there procedures to prevent bar codes from being released to a patient care areas when printer maintenance has not been performed?

 

What promise does the future hold?

Ultimately, health care providers should seek to transition to alternative higher fidelity identification technologies.  However, without standards set for these newer technologies, there will likely be issues with compatibility of the scanners, instruments, and laboratory information systems, making implementation of these technologies complicated.  Use of 2D or matrix bar codes, for example, will require compatible scanners and software to read the more complex bar code symbols and multiple encoded data (as opposed to just one encoded identifier with 1D bar codes). 

 

Other technologies that may be used alone or in combination with bar codes for tracking and identification purposes such as Radio Frequency Identification Devices (RFID) will require an even more thorough investigation prior to implementation.  RFID, in addition to requiring special scanners, require linker software to connect the RFID tag ID to the patient.  RFID broadcasts information and this can be a double-edged sword.  While the broadcast information helps the user locate a RFID encoded specimen, the information may also be accessible to anyone else who happens to have the right equipment to read it.  Therefore, early adopters must also ensure that necessary software is Health Insurance Portability and Accountability Act (HIPAA) compliant (often this software is not)(3).

 

Laboratorians should lead the effort to develop standards for implementing new technologies for patient identification and work with manufacturers to ensure that these new technologies serve to further improve the safety of patient identification across the health care industry.

 

 

 

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About the Author
Corinne Fantz, PhD, DABCC, FACB
Corinne Fantz, PhD, DABCC, FACB 
 

Additional Resources

Mountain PJ, Callaghan JV, Chou D, Davis RR, Hawker CD, Knafel AJ, et al. Laboratory automation: bar codes for specimen container identification; approved standard. 2nd ed. CLSI document AUTO2-A2. Vol. 25. Wayne (PA): CLSI; 2005.

 

Palmer RC. The bar code book: reading, printing, and specification of bar code symbols. 2nd ed. Peterborough, NH, Helmers Publishing; 1991.

 

Hawker CD. Bar codes may have poorer error rates than commonly believed. Clin Chem. 2010 Oct;56(10):1513-4.

 

References

1. Snyder ML, Carter A, Jenkins K, Fantz CR.  Patient Mis-identifications caused by errors in standard bar code technology.  Clin Chem. 2010 Oct;56(10):1554-60. Epub 2010 Aug 11.

 

2. Ansari S, Szallasi A. “Wrong blood in tube”” solutions for a persistent problem. Vox Sang. 2010 Aug 25. [Epub ahead of print]

 

3. Sotto LS. An RFID code of conduct. RFID Journal 2005.