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As laboratory stewardship strategies continue to evolve, numerous interventions are documented in medical literature describing effective strategies to reduce errors when ordering incorrect or inappropriate tests. Many interventions depend on complex algorithms embedded within electronic order systems and can be difficult to implement given always-limited IT resources. Are there more basic things we can do in the laboratory to assist physicians in ordering correct tests? Perhaps there are lessons to be learned from pharmacy Tallman Lettering (TML), and menu psychology.

TML is a useful tool in pharmacy

Laboratory and pharmacy share many similarities. Neither department orders their own services, and both are reliant on appropriate physician orders; any errors ordering the wrong drug or test can have negative implications. This is perhaps truer for pharmacy where medication ordering errors can be immediately life-threatening. For this reason, pharmacists are focused on techniques to ensure correct medication ordering. 

One of the issues contributing to medication errors is the similarity of some drug names to other unrelated look-alike drug names. For example, “hydralazine” (used for hypertension and heart failure) may be easily confused with “hydroxyzine” (an antihistamine). In response, in 2001, the FDA initiated a name differentiation project using TML to help differentiate lookalike drug names.¹ Applying TML to “hydralazine” and “hydroxyzine,” the drug names become “hydrALAZINE” and “hydrOXYzine” to highlight dissimilar letters in otherwise look-alike drug names. Furthermore, TML can incorporate other features such as bolding, differing font sizes and colors to further differentiate look-alike names.¹ While some studies fail to demonstrate significant impact on medication ordering errors, other studies demonstrate positive effects.² Of note, no studies demonstrate negative impact. Adoption of TML for a select number of look-alike drug names to reduce ordering errors is now widespread in the United States and endorsed by organizations including The Joint Commission, the Institute for Safe Medication Practices, and World Health Organization.

Can TML be useful in the laboratory? 

Laboratory test names, like drug names, can often be confused with look-alike laboratory test names. Furthermore, test nomenclature frequently varies between different facilities, sometimes even within the same healthcare system, leading to further confusion. Also complicating nomenclature matters are different testing methodologies for the same analyte which can cause confusion. Given these factors, physicians are often presented with test menus containing look-alike test names representing vastly different tests and/or methodologies making correct test selection a challenge. This is compounded by the time pressure physicians face with already busy workloads.

In some instances, hospital laboratories have already tried to address issues via nomenclature revisions; however, confusion over lookalike test names remain. The application of TML to laboratory test menus, with some modification, might reduce test ordering errors for many tests. Modification to the TML would be necessary, of course, as pharmacy TML highlights key letters in dissimilar drug names—yet physicians are well-versed in the uses of each drug and their clear differences. Comparing this to laboratory test names, it’s not uncommon for physicians to not be fully aware of the differences between two tests with similar names even if key letters were uppercase. For example, if “25-hydoxy vitamin D” and “1,25 dihydoxy vitamin D” were changed to “25-HYDROXY vitamin D” and “1,25-DIHYDROXY vitamin D” or similar format using a derivation of TML, the simple application of uppercase font to dissimilar letters does not further help delineate which test is typically more appropriate in most common clinical scenarios. Perhaps in the case of look-alike laboratory test names within an order entry system, modified TML with the addition of bolding, italics, and font size changes would help physicians more often select tests typically considered appropriate for the majority of common clinical scenarios (Table 1). 

Incorporating TML into the laboratory 

As previously mentioned, TML can incorporate other features such as bolding, differing font sizes, and colors to further differentiate look-alike names. For each example in Table 1 rather than both lookalike test names having uppercase dissimilar letters, generally preferred tests entirely use upper-case letters in larger bold font. The generally less preferred tests use smaller lowercase italicized font. The use of differing font sizes, bolding, and italics are all elements of menu psychology. Menu psychology was first described by Albin Seaberg in 1971, and describes design elements in a restaurant menu to raise the odds of certain items being ordered more frequently than others.³ Specifically, the use of differing font size, capitalization, bold text, and italics could help drive laboratory test menu item selection based on visual hierarchy, perceived importance, and improved learning via von Restorff effect. 

Visual hierarchy is where an element in a visual field stands out attracting attention more strongly than other elements in a visual field making the element seem more important or recommended (perceived importance).⁴ In Table 1, the larger bold text gives the typically preferred tests a higher visual hierarchy. The von Restorff effect, described by Hedwig von Restorff in 1933, describes the phenomenon where in any list of items to be learned, an item that is noticeably different in size or other characteristic tends to be more readily learned and recalled.⁵ Again, the larger bold uppercase text is noticeably different and could contribute to a von Restorff effect for select lookalike test names.

A derivative of TML modified using differing font sizes, along with a combination of other elements such as bold text and italics could possibly decrease test ordering errors in many common clinical scenarios. In instances where the less commonly used lookalike test is still required, the less common tests remain available in the test menu to be readily identified by knowledgeable providers. 

An obvious limitation to implementation of a modified TML may be inherent limitations of an order entry system that does not permit some of the suggested changes. For example, font size changes may be unavailable. Yet some of the suggested changes such as capitalization and bold text are already elements of TML being utilized by pharmacy and so should be easily adapted for laboratory test names.

Understandably the use of test menu psychology to influence provider test ordering represents a possible dilemma for the laboratory. Should laboratory professionals influence selection of certain tests over other lookalike tests using menu psychology? If application of menu psychology is implemented with a focus on patient care to reduce ordering errors and in corroboration with the hospital medical staff the benefits should outweigh the risks—similar to pharmacy TML. Strategies to improve stewardship already include refining nomenclature, best practice alerts, and other interventions specifically aimed at guiding physician choice. In some ways application of TML and menu psychology are alternate methods to change physician ordering patterns we are already striving to influence via other means.

In summary, there may be elements of pharmacy TML along with other modifications employing aspects of menu psychology that positively influence laboratory stewardship for a select number of problematic tests in an order entry menu. For this reason, laboratory professionals should consider this strategy to improve test ordering. Future research in this area, similar to the FDA’s previous 2001 name differentiation project and related follow up studies, may demonstrate the benefits of a modified laboratory TML nomenclature applied to laboratory stewardship to reduce test ordering errors.

References

1. Center for Drug Evaluation and Research (no date) Name differentiation project, U.S. Food and Drug Administration. Available at: www.fda.gov/drugs/medication-errors-related-cder-regulated-drug-products/fda-name-differentiation-project Accessed: 25 June 2024. 
2. (No date) FDA and ISMP lists of look-alike drug names with ... Available at: www.ismp.org/sites/default/files/attachments/2017-11/tallmanletters.pdf Accessed: 25 June 2024. 
3. Pavesic, D. (no date) The Psychology of Menu Design - ScholarWorks@GSU. Available at: scholarworks.gsu.edu/cgi/viewcontent.cgi?article=1000&context=hospitality_facub Accessed: 25 June 2024. 
4. Gordon, K. (2024) Visual hierarchy in UX: Definition, Nielsen Norman Group. Available at: www.nngroup.com/articles/visual-hierarchy-ux-definition/ Accessed: 25 June 2024. 
5. Hunt, R.R. (2015) The subtlety of distinctiveness: What von Restorff really did - psychonomic bulletin & review, SpringerLink. Available at: link.springer.com/article/10.3758/BF03214414 Accessed: 25 June 2024.