Comment

Look out for those medication errors that are just waiting to happen

By R. Idris Hughes

In the editorial in The Pharmaceutical Journal of April 21 (p525) my attention was drawn to the Department of Health report “Building a safer National Health Service for patients”. In that document, hospital pharmacists are praised for introducing good practice to reduce medication errors. The report announces the creation of a National Patient Safety Agency and it describes a variety of implemented or planned safety-related measures. Significantly, the report highlights the mistaken identification of almost identical packaging as “an avoidable cause of error”.

Both this report and that of Professor Toft on intrathecal medication errors presented at a Department of Health press briefing of April 18 (see PJ, April 21, p528) suggest that few adverse incidents result from a single failure. Professor Woods's concomitant report also raises the issue of “confusion by association” as being a contributory causative factor in errors made at the point of medicine selection.

In a related context, The Journal of April 21 (p525) also mentions the labelling and packaging comparisons made on the Patientpacks website (www.patientpacks.com). An appendix at this site attempts to illustrate the dangers introduced by label components that act to initiate confusion through subtle processes of mental association at that critical moment of product selection.

When selecting an item, particularly from among a large assembly of products, any aspect of a package's appearance can trigger the mechanism of confusion. Professor Woods applauds the omission of any reference to the term “intrathecal” on packs containing exclusively intravenous-route products on the grounds that the presence there of the term “intrathecal” might cause confusion by association. This need for such careful attention to detail suggests that the highest degree of overall attention is required in the choice of wording and style of label design for any pharmaceutical product. The latent risk of error occurring in product selection is probably inversely proportional to the prevailing quality of such care in label design.

A popular analogy by James Reason in the BMJ of March 18, 2000 (p768), illustrates latent risk becoming an accident opportunity when each layer of error protection is penetrated. This analogy likens each potentially protective mechanism to an individual slice of Swiss cheese, with each hole representing an imperfection. Errors usually fail to penetrate a whole array of protective slices because the “error opportunity holes” will not be lined up to form an error pathway. If the slices move or the error opportunities shift position (mirroring the rapidly changing situations in a working environment) then successive holes may momentarily line-up to form a “trajectory of accident opportunity”.

These are the realities of accidents — human behaviour is accident prone, regardless of the number of protective slices in place. In any environment it is the protective quality of the individual slices that will most affect the overall level of accident opportunity. The number and size of the holes present in any single layer of protection will be a reliable measure of its protective quality. A single, perfect layer of error protection will eliminate all errors. Conversely, if just one layer presents an abundance of oversize error opportunities then the overall risk of error must be substantially increased.

The process of visually selecting a single item from among many is totally dependent upon the immediate quality of the operative's interpretation of the visually presented information. This quality is, in turn, dependent upon the clarity of that information. Apart from the physical arrangement of the items, relative to one another, clarity of information is the only aid to accurate visual selection. When we pay regard to the intrinsic functions and qualities of the information portrayed on the faces of medicine packages, we should be looking for a distinct layer, or slice, of error protection.

The true proportion of medication errors attributable or partly attributable to confusion triggered by inconsiderate package and label design is unknown. The related incidence of “near misses” is also unknown. Some of Andrea Patel's findings (PJ, November 18, 2000, p744) were noted again in the Journal (April 28, p565), namely, “errors caused by ambiguities in packaging are commonplace” with “different strengths of the same medicine [being] in indistinguishable boxes”. Gregory Petersonand colleagues, of Tasmania, writing in 1999 on the causes and prevention of dispensing errors in the Journal of Clinical Pharmacy and Therapeutics (volume 24, p57), place “improving the packaging and labelling of drug products” among the main factors important in reducing the risk of dispensing errors.

In these reports and those of Professor Toft and Professor Woods, at the website of the United States Institute for Safe Medication Practice (www.ismp.org) and also at Patientpacks and at UCLH Solutions Online (www.uclhsolutions.com), there is ample evidence of a growing, international concern over the clarity and quality of information presented in the packaging and labelling of drug products. Some members of the study group allied to Patientpacks fear that it is this layer, rich in “error opportunity holes”, that contributes most to the failure of error protection protocols. Mrs Patel, also a member of the study group, in the furtherance of her research into this aspect of medication error, is moving the error reporting facility at the University College London Hospitals website to a private facility at Electronic Medicines Management (www.emmsys.com). She will be publishing a collective, ongoing analysis of all the data assembled from the private reports of error in medicine management. Her analysis will include reports from members of all the caring professions, whether posted on the form at the new site or by surface mail on forms that will be made widely available. Pharmacists should welcome and use this facility, demonstrating our recognition of the value and need for a fresh culture of error management in pharmacy, and helping to either discount or substantiate these hypotheses.

Let us hope that the “safety-related measures” to be undertaken by the new National Patient Safety Agency will extend to consideration of the clarity and quality of labelling and packaging in all drug products, and will not simply focus upon those products involved in recent tragic events. The agency should be aware that for each opportunity of error prevention involving an injected product there must be a million more such opportunities with ingested products.