Auto ID Technology
RFID – An Alternative to Barcodes at the Bedside?
Barcoding has become established in several industries as an inexpensive and reliable automatic identification technology that can overcome human error in capturing and validating information. In the decades since its creation, barcoding has become highly standardized, resulting in lower costs and greater accessibility. Indeed, word processors now can produce barcodes, and many inexpensive printers print barcodes on labels. Most current barcode scanners autodiscriminate between 12 and 15 symbologies and all their variants without requiring configuration or programming and, when programming is required, these same barcodes scanners can be programmed for specific uses by simply scanning the appropriate barcodes within the scanner’s user manual.
Despite these significant developments, the adoption of barcoding has been slower in the healthcare sector than the retail and manufacturing sectors. Barcoding can capture and prevent errors during medication administration and is now finding its way from the bedside into support operations within the hospital. A study from Brigham and Women’s Hospital in Boston showed that the number of near misses detected by barcode scanning at the bed side could be cut in half by implementing barcode verification of medications at dispensing or compounding (Cooley, 2008).
Barcoding presents challenges, however, especially with regard to barcode medication administration (BCMA).
- Barcoding requires human compliance—in order to perform its function, a barcode must be scanned and that requires a human to pull the trigger. If a human elects to bypass the process and not use the barcode scanner, there is little that can be done about it.
- Barcodes require line-of-sight scanning. To identify a patient, for example, the care provider must locate and scan the patient’s wristband. If the patient is asleep and resting on that hand, that means disturbing, and possibly waking, the patient.
- The scanner cannot verify that the barcode scanned is actually physically attached to the item it represents. There are well-documented instances of users producing surrogate copies of barcodes and scanning those surrogates, rather than scanning the barcodes actually affixed to the appropriate items (Koppel, et al., 2008).
- Barcode scanners cannot tell the difference between scanning 10 different instances of the same barcode (e.g., scanning 10 different medication vials) or scanning the same barcode 10 times (e.g., scanning the same vial 10 times). This means that people can “cheat” the system, and a user who loses track of where they are in a scanning process cannot tell if they have already scanned an item. It should be noted that the FDA has proposed a serialized National Drug Code (NDC) implementation that would improve this issue.
- When a large number of items must be scanned, users experience fatigue that may result in failure to scan some items, or increase the probability of the user taking shortcuts.
- Barcodes rely on print quality: a damaged barcode may not scan.
- Data is fixed at the time the barcode is printed; it cannot be updated
- Barcode scanning typically requires a flat surface with high contrast. Barcodes on irregular surfaces (such as on a foil-wrapped suppository) or on surfaces without good printed contrast (such as an IV bag) are difficult to scan.
- On some packaging (notably IV bags), the container has multiple barcodes, and the provider cannot always tell which one they should scan.
- Barcode scanning of medications relies heavily on barcodes containing the NDC for which there is not a well-maintained definitive reference list.
Radio-frequency identification (RFID) has been proposed as an alternative to barcoding for medication safety initiatives. RFID uses a microprocessor and an antenna embedded in the labeling of an item (or in the item itself) to provide automated identification in either a passive or active presentation.
In the passive presentation, a transponder (the equivalent of a barcode scanner) sends out a radio wave that activates the microprocessor and causes it to transmit its data contents. Most RFID implementations are passive.
In the active presentation, a battery powers the microprocessor that then continuously “shouts” its data contents to any nearby listening device.
Each microprocessor has a unique identifier, a license plate that uniquely identifies it. Under the auspices of GS1 (www.GS1.org), the electronic product code (www.epcglobalinc.org) standard defines a 96-bit tag identifier that creates enough unique “license plates” to uniquely identify 60,000 doses per day at 10,000 hospitals for over 3 x 1018 years. Other standards use identifiers from 25 to 36 bits long, which still represent up to 68 trillion different identifiers.
Microprocessors can also be configured with writable data sets; the data content of a tag can be updated as changes occur.
Whether active or passive, RFID scanners detect and uniquely identify all tags within their scan field. Typical read rates range between 30 and 60 tags per second.
As a result, RFID technologies address a number of the challenges faced by barcoding systems:
- Less human compliance is required; active systems can produce required scans with no action on the part of the user. For passive systems, a single scan can capture all the items in the scan field.
- Line of sight is not required; RFID scanners have been shown, for example, to be able to positively identify a patient with an RFID wristband even when the patient is sleeping on it.
- When an RFID chip is embedded directly in the item to be identified, there is no way to scan a surrogate.
- The “license plate” ensures that each tag is separately read and uniquely identified.
- Fatigue is reduced because a single scan captures all the tags within its field.
- Print quality and surface geometry do not affect the ability to scan and read the tag.
- There is no need for multiple encoding.
Bedside medication verification (BMV) therefore could become considerably more convenient with RFID. It is conceivable that with just one scan, a nurse could verify patient identity and, medication selection, then document medication administration, including her identity!
Saint Clair Hospital, in Pittsburgh, Pennsylvania, documented just that in 2006. While the team limited its application to certain high-cost or high-risk drugs (and used BCMA for everything else), they were able to document a considerable improvement in medication administration workflow using RFID (Young, 2006).
RFID technologies, however, also have their challenges:
- RFID systems can be deployed across any of a variety of radio frequencies, each of which has specific performance benefits and liabilities, and all of which are mutually exclusive.
- RFID systems are difficult to aim at a single item; they are designed to read every tag within their scan field. As a result, it is difficult to aim the scanner at a single item to identify it.
- Signal strength and data throughput degrade quickly over distance.
- Various environmental conditions (e.g., the presence of certain metals or water) can impede transmission.
- Cost—the passive chips themselves are priced between $0.05 and $0.10 in quantity (meaning in the millions). After the addition of the chip and antenna to the carrier (such as a label, or a pharmaceutical container) the unit price rises to $0.50. Active tags cost approximately $50.
It is encouraging, therefore, that these technologies are not mutually exclusive, as the Saint Clair report demonstrates.
For the time being, the high cost of implementation appears to continue to be a barrier for most patient safety applications. Currently, hospitals are deploying these systems primarily for asset tracking, using active tags with real-time location systems (RTLS) to capture up-to-the-minute information about the location of expensive equipment. Some hospitals are considering leveraging these RTLS systems to maintain similar information about patients and staff. It is likely, however, that the price per tag will have to fall significantly before it becomes practical to use RFID for medication safety initiatives.