Barcode symbology

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Medication safety has been a center of focus among the public and health care professionals in recent years. Leape et al. reported a significant 38% of medication errors occur during nurse administration. Barcode technology has since been considered a potential strategy to address these errors at point of administration. Many institutions had also embarked on a journey to improve quality of care and patient safety with this point of care devices. One of the considerations and challenges to implement barcode medication administration (BCMA) is the knowing and deciding the type of barcode to use. Knowledge of barcode symbology and anatomy is important in making considerations and decision in BCMA implementation and integrating barcode technology into complex hospital workflow.


Most medication barcode requires the minimum national drug code (NDC), which contain information on the labeler (drug company), drug, form, strength and package code.

Data Format

NDC is 10 digit with a single “check digit” necessary for ascertaining data integrity. It comprises of 3 segments. The first segment, labeler code, is assigned by the U.S. Food and Drug Administration (FDA) upon submission of a Labeler Code Request. The second segment, product segment, identifies the strength, dosage form, and formulation. The third segment, package segment, identifies package forms and sizes.


Symbology is to barcoding what font is to written word. Generally two major type of symbologies used in health care: linear and two- dimensional (2D).

Linear symbologies

Linear symbologies encode data using alternating black and white spaces. Examples are code 39, code 128 and UPC-A. Real main advantage arises from the fact they have been around for decades and virtually any laser scanner could scan it. Disadvantage is that linear symbologies tend to be longer than their 2-D counterpart. Spacing of alternating black and white lines can be distorted on uneven surface like patient wrist band affecting scans. A new linear Reduced Space Symbology (RSS) has been introduced to address limitations of small medication packages.

Two dimensional (2-D) symbology is referred to as digital identifier. Examples are Data Matrix and PDF 417. 2D symbologies have greater data density potential for labeling small medication items as compared to linear counterparts. Advantage includes allowing scan from any direction. This can minimize disturbance to sleeping patient while nurse is administering intravenous medications. Data Matrix and PDF417 create symbols fail only once per 612 million scans as compared to error rates with Code 128 which is about one per 37 million. Drawback of 2D symbologies is the higher cost for implementation. Conventional linear charge-coupled device (CCD) scanners cannot scan 2D symbologies.

Type of symbology to use for medication barcode, staff identifier and patient wrist band are important consideration prior to BCMA implementation as it could impact hardware, cost and workflow.

Submitted by: Darren Lim


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