LAUSR

Objective To evaluate age-banded dosing in paediatric inpatients by determining the proportion of patients whose dose would fall outside the therapeutic range (by weight). Design A retrospective observational study. Weight and height measurements and details of hospital admissions were matched from the electronic patient record of a single, tertiary paediatric hospital. Dosage which would be given according to age-banded dosing was then compared with their weight. Participants All children admitted to a single tertiary children’s hospital aged 3 months to 16 years over a 5-year period. Data were cleaned to remove values likely to be erroneous and filtered to reduce bias due to patients who were admitted on multiple occasions. Outcomes The main outcome was the proportion of patients who would receive a subtherapeutic or supratherapeutic paracetamol dose if given a dose based on their age. Secondary outcomes were to examine this in children of different ages and to examine the impact of alternative size-based dosing strategies. Results 100 047 admissions (in 68 310 patients) had a weight documented. If age-banded dosing had been used, a subtherapeutic dose (less than 10 mg/kg) would be given during 19 829 (20%) of the admissions and a supratherapeutic dose (over 18.75 mg/kg, 75 mg/kg/day in four doses) in 4289 (4.3%). The highest risk of a subtherapeutic dose occurred in infants just prior to reaching 6 months of age (83%) and in children just prior to reaching 8 years (66%). The highest risk of a supratherapeutic dose was at 12 years of age (35%). Conclusion Age-banded dosing is not suitable for an inpatient paediatric population as approximately a quarter of patients receive a dose outside the recommended range of 10.0–18.75 mg/kg.