The epidemiology of mortality and treatment of people with epilepsy
The UK National General Practice Study of Epilepsy (NGPSE) is a prospective, population based study of newly diagnosed epilepsy including acute symptomatic seizures and single seizures. Patients were followed for 11,400 person years (median follow-up 25 , 75 centiles is 11.8 years 10.6-12.7 ). Out of 564 patients with definite and 228 with probable epilepsy, 149 and 50 deaths respectively were analysed. Long-term mortality was twice that of the general population (standardized mortality ratio SMR 2.1 95% Confidence interval (CI)=1.8,2.4 ). Multivariate Cox regression and time dependent co-variate analyses were utilised for the first time in a study of mortality in epilepsy. Patients with generalised tonic clonic seizures had an increased risk of mortality (hazard ratio or HR 6.2 95%CI=1.4,27.7 p=0.049 ). Time dependent co-variate analysis examined the influence of ongoing factors on mortality. Seizure recurrence (HR 1.30 95%CI=0.84,2.01 ) and AED treatment (HR 0.97 95%CI=0.67,1.38 ) did not influence mortality. Treatment patterns in 564 patients with definite epilepsy were followed prospectively for 11-14 years. Treatment was started in 433 (77%) patients. Only 15% of single seizure (index seizure = first seizure) cases had any medication prescribed initially. Due to subsequent seizure recurrence, more than 70% of these patients ultimately received antiepileptic medication. 209/564 patients (37%) were on treatment for epilepsy at last follow-up. 98/209 (47%) of those on treatment were in 5-year terminal remission. Figures from this study suggest that of 30,000 patients newly diagnosed with epilepsy every year in the United Kingdom, approximately 6000 have inadequate seizure control in the long term. A third of the patients in this group have one or more seizures monthly. Only 2/3rds of these patients with frequent seizures had switched medication in order to try and achieve better seizure control. There is probably still considerable room for improvement in prescribing practice in the UK.