Health literacy predicts pediatric dosing accuracy for liquid zidovudine

Abstract

Objectives: Little is known about adult caregivers’ ability to accurately dose pediatric antiretroviral medications. We aimed to characterize the frequency of dosing errors for liquid zidovudine using two dosing devices and to evaluate the association between HIV literacy and dosing errors in adults living with HIV infection. Design: Cross-sectional study enrolling 316 adults receiving combination antiretroviral therapy (cART) for HIV infection in Maputo Province, Mozambique. Methods: Participants were administered the HIV Literacy Test (HIV-LT) and asked to measure 2.5 ml of liquid zidovudine using both a cup and syringe. Dosing measurement errors for liquid zidovudine were defined as ‘any error’ (≥20% deviation from reference dose) and ‘major error’ (≥40% deviation from reference dose). Results: Dosing errors were common using the cup (any error: 50%, major error: 28%) and syringe (any error: 48% of participants, major error: 28%). There were no significant differences in proportions of any dosing error (P = 0.61) or major dosing errors (P = 0.82) between dosing instruments. In multivariable models, associations (P ≤0.03) were found between higher HIV-LT score and dosing errors for both the cup [any error adjusted odds ratio, AOR: 0.91 (0.84–0.99), major error AOR: 0.84 (0.75–0.92)] and syringe [any error AOR: 0.82 (0.75–0.90), major error AOR: 0.88 (0.80–0.97)]. Conclusion: Liquid antiretroviral medications are critical for prevention and treatment of pediatric HIV infections, yet dosing errors were exceedingly common in this population and were significantly associated with lower HIV literacy levels. Targeted interventions are needed to improve HIV knowledge and skills for pediatric medication dosing, particularly for caregivers with limited literacy.