Use of a Pictographic Diagram to Decrease Parent Dosing Errors With Infant Acetaminophen: A Health Literacy Perspective

OBJECTIVE: Medication dosing errors by parents are frequent. We sought to whether a pictographic dosing diagram could improve parent ability to dose infant acetaminophen, and to determine whether pictogram benefit varies by health literacy level. METHODS: We conducted an experimental study of parents presenting with their children to an urban public hospital pediatric clinic. Caregivers were randomized to dose infant acetaminophen with a standard dropper using text-only or text-plus-pictogram instructions (pictographic diagram of dose). The primary outcome variable was dosing accuracy (error defined as >20% deviation above/below dose; large overdosing error defined as >1.5 times recommended dose). Caregiver health literacy was assessed by means of the Newest Vital Sign measure. RESULTS: A total of 299 parents were assessed (144 text-only instructions; 155 text plus pictogram); 77.9% had limited health literacy (Newest Vital Sign score 0-3). Text-plus-pictogram recipients were less likely to make an error compared to text-only recipients (43.9% vs 59.0%, P = .01; absolute risk reduction, 15.2% [95% confidence interval, 3.8-26.0]; number needed to treat, 7 [4-26]). Of text-plus-pictogram recipients, 0.6% made a large overdosing error compared to 5.6% of text-only recipients (absolute risk reduction, 4.9% [0.9-10.0]; number needed to treat, 20 [10-108]). Pictogram benefit varied by health literacy, with a statistically significant difference in dosing error evident in the text-plus-pictogram group compared to the text-only group among parents with low health literacy (50.4% vs 66.4%; P = .02), but not for parents with adequate health literacy (P = .7). CONCLUSIONS: Inclusion of pictographic dosing diagrams as part of written medication instructions for infant acetaminophen may help parents provide doses of medication more accurately, especially those with low health literacy. High error rates, even among parents with adequate health literacy, suggest that additional study of strategies to optimize dosing is needed.