Mathematics Anxiety and Mathematics Self-efficacy in Relation to Medication Calculation Performance in Nurses Page: 42

                                
Ulanimo et al. (2007) investigated nurses' perceptions of causes of medication errors and found
10 frequent causes of medication errors (see Table 3): first, not following routine procedure;
second, fatigue; and fourth, dose miscalculation by nurse. Studies may not be able to measure
calculation errors directly, but nurses perceive that calculation errors are a common cause of
medication errors.
Some tasks are prone to error, for example, a task with which the person is unfamiliar and
is trying to accomplish under pressure, such as setting up an infusion device or drawing up
pediatric medication in an emergency, or doing a multistep mathematics problem related to a
critical infusion while everyone is waiting. Medication administration requiring a calculation of a
dosage or dilution is especially susceptible to error (McDowell et al., 2009). Medication errors
are more common in pediatrics and intensive care and often involve multistep calculations and
require the use of infusion devices. Gladstone (1995) reviewed 79 incident reports and found that
more than 50% of the medication errors were dose related, and the majority of those were
incorrect infusion rates (17.7%). Improving mathematic skills may be one way to decrease
calculation issues.
Calculations involved in most medication calculations are estimated to be at a seventh-
grade mathematics level or below (Polifroni et al., 2003; Rainboth & DeMasi, 2006). Most
calculations involve simple arithmetic, multiplication, division, fractions, decimals, percentages,
and conversions to the metric system. The most difficult mathematics required in medication
calculation involves multiple steps such as when calculating weight-based doses and IV infusion
rates. Some IV infusions have to be given based on a dose of micrograms per kilogram per
minute, and the infusion pump is set in milliliters per hour. The calculation of weight-based
doses and/or infusion rates would be most difficult for the nurse who cannot do the simpler dose

42