Using name overlap analysis to understand medication name search safety

To examine the degree of left-to-right character overlap in medication names as they appear in real-world computer systems.

We programmed a computer to create and automatically analyze left-to-right character overlap in names appearing on 20,020 lists of real-world medication names. The lists varied in length from 100 to 500 medication names and were created by randomly drawing names from a pool of 2,249 medication names extracted from an operating medication use system database.

Overall maximum left-to-right character overlap varied in lists of 100 to 500 medication names from 4 to 29 characters (mode of 14 characters). For a small subset of names for high-alert medications that must never be administered in error, overall maximum left-to-right character overlap varied from 3 to 10 characters (mode of 6 characters). Further, for users searching for medications by name in computer systems, the keystrokes that do the most work to disambiguate medication names on a list are always the initial few keystrokes.

Medication name left-to-right character overlap on lists of names searched ranges widely. Instead of requiring all users to type a set number of characters when searching for medications by name, search safety can potentially be improved by upgrading computer systems to dynamically respond to each keystroke entered. Using incremental dynamic search, searchers would often be able to type fewer than 5 characters to isolate a single medication by name but would sometimes have to type many more than 5 characters to do so.