PTCE - Patient Safety and Quality Assurance - Section 3.2

Apply error prevention strategies, including correct-patient verification, Tall Man lettering, inventory separation, leading and trailing zeros, bar code usage, and avoidance of error-prone abbreviations.

Apply error prevention strategies including Tall Man lettering, leading zeros (never trailing zeros for whole numbers), bar code medication administration, correct-patient verification, and avoidance of ISMP error-prone abbreviations. Choose the most appropriate strategy for a given dispensing or administration error risk.

Tall Man letteringLeading zeroBar code medication administrationError-prone abbreviation

Practice question for this objective

Free samplePatient Safety and Quality Assurancemedium

A technician is taught the rules for how doses should appear on a label to prevent tenfold dosing errors. Which way of expressing a dose follows the recommended convention for leading and trailing zeros?

AWriting the dose as 0.5 mg so that a leading zero precedes the decimal point. Correct
BWriting the dose as 5.0 mg so that the decimal point clearly marks a whole number.
CWriting the dose as .5 mg so that the figure stays compact on the label.
DWriting the dose as 5.00 mg to show that the strength has been verified to two places.

Apply the rule that doses below one take a leading zero while whole numbers omit a trailing zero to prevent tenfold errors. A leading zero in front of a decimal fraction signals that a decimal point follows, while a trailing zero on a whole number can be misread as a tenfold larger dose if the point is overlooked, so the safe convention uses the leading zero and drops the trailing zero.

Why A is correct: Correct. A leading zero before a decimal less than one alerts the reader to the decimal point, preventing a tenfold overdose if the point is faint or missed.

Why B is wrong: A trailing zero is tempting because it looks precise, but if the decimal point is missed the dose reads as 50 mg. Trailing zeros are discouraged, so this is wrong.

Why C is wrong: A naked decimal is tempting for brevity, but a missed point reads as 5 mg. A leading zero must be added before the decimal, so this is wrong.

Why D is wrong: Extra trailing zeros suggest false precision and amplify the misread risk if the decimal is overlooked. Trailing zeros should be omitted, so this is wrong.

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