Prescribed medicine use and extent of off-label use according to age in a nationwide sample of Australian children

Abstract

BACKGROUND: Medicine prescribing for children is impacted by a lack of paediatric-specific dosing, efficacy and safety data for many medicines. OBJECTIVES: To estimate the prevalence of medicine use among children and the rate of 'off-label' prescribing according to age at dispensing. METHODS: We used population-wide primarily outpatient dispensing claims data for 15% of Australian children (0-17 years), 2013-2017 (n = 840,190). We estimated prescribed medicine use and 'off-label' medicine use according to the child's age (<1 year, 1-5 years, 6-11 years, 12-17 years) defined as medicines without age-appropriate dose recommendations in regulator-approved product information. Within off-label medicines, we also identified medicines with and without age-specific dose recommendations in a national prescribing guide, the Australian Medicines Handbook Children's Dosing Companion (AMH CDC). RESULTS: The overall dispensing rate was 2.0 dispensings per child per year. The medicines with the highest average yearly prevalence were systemic antibiotics (435.3 per 1000 children), greatest in children 1-5 years (546.9 per 1000). Other common medicine classes were systemic corticosteroids (92.7 per 1000), respiratory medicines (91.2 per 1000), acid-suppressing medicines in children <1 year (47.2 per 1000), antidepressants in children 12-17 years (40.3 per 1000) and psychostimulants in children 6-11 years (27.0 per 1000). We identified 12.2% of dispensings as off-label based on age, but 66.3% of these had age-specific dosing recommendations in the AMH CDC. Among children <1 year, off-label dispensings were commonly acid-suppressing medicines (35.5%) and topical hydrocortisone (33.1%); in children 6-11 years, off-label prescribing of clonidine (16.0%) and risperidone (13.1%) was common. Off-label dispensings were more likely to be prescribed by a specialist (21.7%) than on-label dispensings (7.5%). CONCLUSIONS: Prescribed medicine use is common in children, with off-label dispensings for medicines without paediatric-specific dosing guidelines concentrated in classes such as acid-suppressing medicines and psychotropics. Our findings highlight a need for better evidence to support best-practice prescribing.