DISPENSING EPILEPSY MEDICATION - A METHOD OF DETERMINING THE FREQUENCY OF SYMPTOMATIC INDIVIDUALS WITH SEIZURES

We estimated the prevalence and incidence of epilepsy in The Netherlan ds using drug-dispensing information from the PHARMO database, contain ing medication histories of nearly 300,000 individuals. An algorithm b ased on antiepileptic drug prescription records was used to identify p atients with epilepsy requiring medication for seizure control. The al gorithm was validated by comparing positive algorithm identifications to medical diagnoses from general practitioners and hospital records. In 1990-1991, the algorithm revealed 1158 patients with ''certain'' ep ilepsy, and 451 patients with ''probable'' epilepsy. Epilepsy was pres ent in 93% of patients on polytherapy, and 58% on monotherapy. Clonaze pam monotherapy was non specific for epilepsy. The use of carbamazepin e monotherapy for epilepsy was age-dependent. After correcting the alg orithm for these drugs, and standardizing to the Dutch population, the point prevalence of epilepsy was 4.8/1000 (95% CI: 4.5-5.0). The inci dence rate was 0.72/1000 person-years (95% CI: 0.65-0.79). Using drug- dispensing data for epilepsy medication, it is possible to make valid estimations of the number of epilepsy patients requiring drug therapy. (C) 1997 Elsevier Science Inc.