Systematic derivation of an Australian standard for Tall Man lettering to distinguish similar drug names

Emmerton, Lynne, Rizk, Mariam F. S., Bedford, Graham and Lalor, Daniel (2015) Systematic derivation of an Australian standard for Tall Man lettering to distinguish similar drug names. Journal of Evaluation in Clinical Practice, 21 1: 85-90. doi:10.1111/jep.12247

Author Emmerton, Lynne
Rizk, Mariam F. S.
Bedford, Graham
Lalor, Daniel
Title Systematic derivation of an Australian standard for Tall Man lettering to distinguish similar drug names
Journal name Journal of Evaluation in Clinical Practice   Check publisher's open access policy
ISSN 1365-2753
Publication date 2015-02-01
Year available 2014
Sub-type Article (original research)
DOI 10.1111/jep.12247
Open Access Status
Volume 21
Issue 1
Start page 85
End page 90
Total pages 6
Place of publication Chichester, West Sussex United Kingdom
Publisher Wiley-Blackwell Publishing
Collection year 2015
Language eng
Formatted abstract
Rationale, aims and objectives

Confusion between similar drug names can cause harmful medication errors. Similar drug names can be visually differentiated using a typographical technique known as Tall Man lettering. While international conventions exist to derive Tall Man representation for drug names, there has been no national standard developed in Australia. This paper describes the derivation of a risk-based, standardized approach for use of Tall Man lettering in Australia, and known as National Tall Man Lettering.


A three-stage approach was applied. An Australian list of similar drug names was systematically compiled from the literature and clinical error reports. Secondly, drug name pairs were prioritized using a risk matrix based on the likelihood of name confusion (a four-component score) vs. consensus ratings of the potential severity of the confusion by 31 expert reviewers. The mid-type Tall Man convention was then applied to derive the typography for the highest priority drug pair names.


Of 250 pairs of confusable Australian drug names, comprising 341 discrete names, 35 pairs were identified by the matrix as an ‘extreme’ risk if confused. The mid-type Tall Man convention was successfully applied to the majority of the prioritized drugs; some adaption of the convention was required.


This systematic process for identification of confusable drug names and associated risk, followed by application of a convention for Tall Man lettering, has produced a standard now endorsed for use in clinical settings in Australia. Periodic updating is recommended to accommodate new drug names and error reports.
Keyword Confusion
Look-alike sound-alike
Tall Man
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online ahead of print 19 Oct 2014

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
Official Audit
School of Medicine Publications
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