In late May 2010, the Consortium for the Advancement of Patient Safety (CAPS) told a meeting of the US Pharmacopeia’s (USP’s) Nomenclature Expert Committee that the latter’s proposal to restrict printing on ferrules and cap overseals was ambiguous and could unintentionally reduce patient safety. CAPS’s comments were based on a three-part study that the group commissioned to evaluate USP’s proposed revision of USP
General Chapter <1>, “Injections, Labeling on Ferrules and Cap Overseals,” which is scheduled to become effective in May 2011.
USP had held that healthcare professionals should rely exclusively on package inserts and vial labels for information about drug products. The organization proposed limiting cap messages to a small set of drugs that pose a risk of imminent harm or death in the event of medication errors. In 2009, a representative of the US Food and Drug Administration recommended that a human-factors engineering study be conducted to provide data to evaluate USP’s proposal.
CAPS hired Anthony Andre, founding principal of Interface Analysis Associates and adjunct professor of human factors and ergonomics at San Jose State University, to study the relationship between patient safety and messages on ferrule and cap overseals. The resulting three-phase study includes a literature review; an online survey of healthcare practitioners, which was conducted in December 2009; and a human-factors research study, in which healthcare practitioners participated in March 2010.
Andre’s literature review did not find any reported incidents of medication errors that were associated with cap messages. In addition, the human-factors principles found in scientific literature did not support the premises of USP’s proposal.
The majority of respondents to the online survey of healthcare practitioners said that the USP proposal would prohibit important cap messages. About 80% of respondents predicted that medication errors would increase if many of the currently allowed cap messages were prohibited. Roughly 69% of respondents disagreed with USP’s approach to making warnings more prominent for healthcare professionals.
Participants in the empirical human-factors study had to select the correct drug from a group of drug vials, some of which had cap labels that would be prohibited by the USP proposal, and some of which did not. Participants selected drugs with cap labels more accurately and more quickly than they selected unlabeled drugs, according to the report. Participants rated the labeled drugs as easy to use more often than the unlabeled drugs. The 20 participants included nurses, physicians, and pharmacists who normally handle drug vials and check drugs against prescriptions.
“The science of human factors, coupled with our recent research, shows that the cap area is an underutilized and highly visible area of the drug vial that is well-suited to present key medication and warning information toward aiding healthcare practitioners in selecting the correct drug in the correct concentration and dose,” said Andre in a CAPS press release