PRESCRIBING PRACTICES IN CHILDHOOD EPILEPSY: USE OF A POPULATION HEALTH CARE DRUG DATABASE

Objectives: Population based drug databases provide a cost effective means to study current prescribing patterns and changing trends in antiepileptic drug (AED) utilization. We describe the prescribing practices of physicians in Manitoba treating children with epilepsy in the first 6 years of life using a population drug database.

Methods: A 1995 birth cohort was assembled for the province of Manitoba, Canada, from health care database records for a complete population in the setting of universal health care insurance, and linked with the prescription drug database. Children with actively treated epilepsy, as defined by the presence of an ICD-9 diagnosis code (345, 780,779) from a hospitalization, physician visit, with a concurrent prescription of an AED followed by subsequent usage of AED refills within twelve months, were identified over a 7 year period (1995–2001).

Results: The prevalence of actively treated epilepsy in Manitoba children was 6.25/1000 with a mean age of diagnosis of 2.75 years (SD 1.89). The most commonly prescribed AEDs included: Phenobarbital (35.3%), Carbamazepine (25.6%) and Valproic Acid (18%). Newer anticonvulsants were prescribed less frequently. Only 22% of all prescriptions for AEDs were prescribed by a neurologist. A total of 6.1 AED prescriptions/epilepsy person years were prescribed. Continuous AED use was seen in 37% of all children. The total cost of AED drugs over the study period was $152/person/epilepsy person year.

Conclusion: This is the first study to use a population-based approach to describe AED prescribing practices in Canadian children. The longitudinal pattern of AED selection and changes made during course of treatment were explored. Access to AEDs is influenced by location and regional disparities in level of health care expertise available.