Epidemiological study of epilepsy by monitoring prescriptions of antiepileptic drugs.

The aim of this study is to evaluate a simple and effective method of acquiring epidemiological information about epilepsy. Data on antiepileptic drug prescriptions was collected, the utilization pattern being based on defined daily doses (DDDs). Antiepileptic drugs are epidemiological tracers of epilepsy due to their chronic and highly specific usage. Consequently, a prevalence rate for the whole population may be obtained by using DDDs. Data on antiepileptic drug prescriptions for a period of 6 months in 1992 and 6 months in 1993 indicate a utilization of approximately 7 DDDs of antiepileptic drugs per 1,000 inhabitants. The prevalence of epilepsy was estimated by correcting the exposure calculated in DDDs by a factor of 0.68. In our sample, the prevalence of the disease was 5.2 per 1,000 inhabitants in 1992 and 4.9 per 1,000 in 1993. Physician prescriptions were concentrated on four compounds, namely phenobarbital, carbamazepine, valproic acid and phenytoin, which together represented 90% of total antiepileptic drug prescriptions.