If you’re preparing to meet electronic pedigree rules or hoping for efficiencies from automatic identification, you’ll find this issue’s Bar Coding Supplement useful. Ralph Dillon and Joseph Noferi, who have written about bar codes for PMP News before, join Feargal McGroaty and Lucas Lindsey to offer examples of effective bar code use in other industries. The utility they find bar codes to offer elsewhere should be encouraging to healthcare product packagers. Complete drug traceability doesn’t seem so impossible.
But as potential pedigree builders know, the bar code’s one sticking point is that to read it, you always need line of sight for every bar code.
Or do you?
“Bar codes work in serial tracking through the concept of ‘inference,’” says Dillon. “Although some misinformed pundits of RFID have proclaimed that every [individually bar coded] item would need to be scanned, tamper evidence has long been used in the shipping system to ensure that the items packed in cases are still inside and intact until the case is opened.” Dillon explains that “if a case is packed with a series of items and the tamper evidence is still intact, then it can be inferred that all the packed serial numbers are inside.” For instance, if “case #D = Serial #X1 through X24, then only the case number needs to be read to know the serial numbers inside. Rolled into bar codes, this approach means that all the items in a case can be inferred by the IT systems from the bar code on the case.” Likewise, “a single bar code on a tamper-evident pallet can be used to infer all the cases and, in turn, all the items,” he says.
But some still worry. Would inferred products carry pedigrees with asterisks? At recent meetings on electronic pedigrees, the California Board of Pharmacy’s (CA BoP) enforcement committee has questioned the concept of inference. Their concern seems to be one of responsibility. If inference is permitted and inferred product turns up missing, who would be responsible? How could pedigree builders guarantee the presence of product they hadn’t actually verified? Would a certified and transferred electronic pedigree for missing product call into question the true worth of an electronic pedigree?
Dillon points out that inference is already being allowed by pedigree legislation in Florida as well as by the Bollini legislation in Italy.
And inference may have to be permitted even if non-line-of-sight technologies were to prevail. “If the RFID does not read, or if it has to be disabled for privacy issues, the [redundant] bar code remains as an efficient method to capture the critical code,” he says. This brings the supply chain back to relying on inference.
Given the news that many drug manufacturers are basing their pedigree programs on serialized 2-D Data Matrix, the CA BoP may have little choice but to allow inference.
Inference isn’t really a new concept. As one speaker reminded the audience at a CA BoP meeting, pharmacists infer the contents of the bottles they receive from manufacturers from their labeling. And patients infer the contents of their prescriptions based on pharmacy labeling. Inference is common and accepted.
So what do we infer from that?