Effect of Medication Label Units of Measure on Parent Choice of Dosing Tool: A Randomized Experiment

Some experts recommend eliminating "teaspoon" and "tablespoon" terms from pediatric medication dosing instructions, because these terms could inadvertently encourage use of nonstandard tools (ie, kitchen spoons), which are associated with dosing errors. We examined whether use of "teaspoon" or "tsp" on prescription labels affects parents' choice of dosing tools, and the role of health literacy and language.

Analysis of data collected as part of a controlled experiment (SAFE Rx for Kids [Safe Administration For Every Prescription for Kids] study), which randomized English- and Spanish-speaking parents (n = 2110) of children 8 years of age and younger to 1 of 5 groups, which varied in unit of measurement pairings on medication labels and dosing tools. Outcome assessed was parent self-reported choice of dosing tool. Parent health literacy was measured using the Newest Vital Sign.

Seventy-seven percent had limited health literacy (36.0% low, 41.0% marginal); 35.0% completed assessments in Spanish. Overall, 27.7% who viewed labels containing either "tsp" or "teaspoon" units (alone or with "mL") chose nonstandard dosing tools (ie, kitchen teaspoon, kitchen tablespoon), compared with 8.3% who viewed "mL"-only labels (adjusted odds ratio [AOR] = 4.4 [95% confidence interval (CI), 3.3-5.8]). Odds varied based on whether "teaspoon" was spelled out or abbreviated ("teaspoon"-alone: AOR = 5.3 [95% CI, 3.8-7.3]); "teaspoon" with mL: AOR = 4.7 [95% CI, 3.3-6.5]; "tsp" with mL: AOR = 3.3 [95% CI, 2.4-4.7]; P < .001). Similar findings were noted across health literacy and language groups.

Use of teaspoon units ("teaspoon" or "tsp") on prescription labels is associated with increased likelihood of parent choice of nonstandard dosing tools. Future studies might be helpful to examine the real-world effect of eliminating teaspoon units from medication labels, and identify additional strategies to promote the safe use of pediatric liquid medications.