Unit of Measurement Used and Parent Medication Dosing Errors

Abstract

BACKGROUND AND OBJECTIVES: Adopting the milliliter as the preferred unit of measurement has been suggested as a strategy to improve the clarity of medication instructions; teaspoon and tablespoon units may inadvertently endorse nonstandard kitchen spoon use. We examined the association between unit used and parent medication errors and whether nonstandard instruments mediate this relationship. METHODS: Cross-sectional analysis of baseline data from a larger study of provider communication and medication errors. English- or Spanish-speaking parents (n = 287) whose children were prescribed liquid medications in 2 emergency departments were enrolled. Medication error defined as: error in knowledge of prescribed dose, error in observed dose measurement (compared to intended or prescribed dose); >20% deviation threshold for error. Multiple logistic regression performed adjusting for parent age, language, country, race/ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease; site. RESULTS: Medication errors were common: 39.4% of parents made an error in measurement of the intended dose, 41.1% made an error in the prescribed dose. Furthermore, 16.7% used a nonstandard instrument. Compared with parents who used milliliter-only, parents who used teaspoon or tablespoon units had twice the odds of making an error with the intended (42.5% vs 27.6%, P = .02; adjusted odds ratio=2.3; 95% confidence interval, 1.2–4.4) and prescribed (45.1% vs 31.4%, P = .04; adjusted odds ratio=1.9; 95% confidence interval, 1.03–3.5) dose; associations greater for parents with low health literacy and non–English speakers. Nonstandard instrument use partially mediated teaspoon and tablespoon–associated measurement errors. CONCLUSIONS: Findings support a milliliter-only standard to reduce medication errors.

Liquid Medication Errors and Dosing Tools: A Randomized Controlled Experiment

“…Previous studies have demonstrated high error rates with liquid medications. 12,13,15,16 A range of definitions for error have been used in the literature, with some relying on specific deviations in amount (eg, 0.2 mL), 21 whereas others use percentage deviations (eg, 10%, 20%). 16,37 We defined an error as >20% deviation, because we hoped to identify strategies that could be universally applied as part of a public health approach, recognizing that some medications have a narrow therapeutic window.…”

“…22 A study of prescribed products found that more than a third of the time, the label did not contain the same units as the prescription. 13 Recently, the AAP issued a policy statement endorsing a move to a milliliterexclusive system and avoidance of terms such as teaspoon and tablespoon, 7 a stance consistent with that of other organizations, including the FDA and the American Academy of Family Physicians, 20, 30 -32 but there are concerns that such a move could result in greater confusion because parents may be comfortable dosing using teaspoon and tablespoon terms and unfamiliar with milliliter units 7,13 ; the United States has had a long-standing dependence on nonmetric units. 33 In this study, we sought to fill gaps in evidence about best practices for the labeling and dosing of pediatric liquid medications.…”

Prevalence of Unrounded Medication Doses and Associated Factors Among Hospitalized Pediatric Patients

“…In one study, parents whose children were prescribed oral liquid medication in the emergency department were assessed to see if they could accurately measure the dose of liquid medications. 11 The investigators found 41.1% of parents made an error in measuring the prescribed dose. It is very probable that these unrounded doses may lead to even greater complexity in administering medications and could lead to an increase in dose-dependent ADEs or subtherapeutic doses.…”

Factors Associated With Dispensing Dosage Delivery Devices

“…2,4,10 Another recent study reported that parents who used teaspoon or tablespoon units were more likely to make an error in dosage than parents who only used milliliter measurements for both the dose they intended to give and the prescribed dose. 11 In May 2011, the Food and Drug Administration finalized voluntary guidelines to industry addressing various issues including the lack of dose devices for orally administered over-the-counter liquid medications and stated that dose devices should be in metric units rather than in teaspoons or tablespoons. 12 Various public health agencies, consumer and patient advocate groups, and academic experts have issued similar recommendations regarding the importance of metricbased doses for all pediatric liquid medications, 13,14 and the American Academy of Pediatrics has specifically advocated use of metric-based oral syringes for administering liquid medications to children.…”