Predictors of misunderstanding pediatric liquid medication instructions.
OBJECTIVE
Our objective was to determine the level of adult understanding of dosage instructions for a liquid medication commonly prescribed for children.


METHODS
Structured interviews were conducted with 373 adults waiting for an appointment at family medicine clinics serving low-income populations in Shreveport, La; Chicago; and Jackson, Mich, from July 2003-August 2004. Subjects were asked to read a prescription label for amoxicillin and explain how they would take the medication. Correct interpretation was determined by a panel of blinded physician reviewers who coded subjects' verbatim responses. Qualitative methods were used to determine the nature of incorrect responses.


RESULTS
Twenty-eight percent of subjects misunderstood medication instructions. The prevalence of misinterpreting instructions among subjects with adequate, marginal, and low literacy was 18%, 34%, and 43%, respectively. Common causes for misunderstanding included problems with dosage measurement (28%; ie, tablespoon instead of teaspoon) and frequency of use (33%; ie, every 3 hours instead of every 6-8 hours). In an adjusted analysis that excluded literacy, African Americans were more likely to misunderstand instructions than Caucasians (adjusted odds ratio [AOR] 1.63, 95% confidence interval [CI]=1.02-2.61). When literacy was included in the model, the effect of race on misunderstanding was reduced and nonsignificant. Inadequate and marginal literacy remained independent predictors of misunderstanding (inadequate--AOR 2.90, 95% CI= 1.41-6.00; marginal--AOR 2.20, 95% CI=1.19-3.97).


CONCLUSIONS
Misinterpretation of pediatric liquid medication instructions is common. Limited literacy is a significant risk factor for misunderstanding and could contribute to racial disparities. Instructions should be written in a concise manner and standardized to ensure comprehension.
Bailey
Stacy Cooper
SC
Health Literacy and Learning Program, Center for Communication in Healthcare, Northwestern University, Chicago, IL 60611, USA. stacy-bailey@northwestern.edu
Pandit
Anjali U
AU
Yin
Shonna
S
Federman
Alex
A
Davis
Terry C
TC
Parker
Ruth M
RM
Wolf
Michael S
MS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000008:administration & dosage; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D032882:Comprehension; D054796:Drug Dosage Calculations; D011307:Drug Prescriptions; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008508:Medication Errors / Q000517:prevention & control*; D008875:Middle Aged; D010353:Patient Education as Topic / Q000379:methods / Q000592:standards*; D011203:Poverty; D044469:Racial Groups; D016037:Single-Blind Method; D055815:Young Adult
D000900:Anti-Bacterial Agents; D000658:Amoxicillin