Every year in the UK, around 1,000 people die from causes related to epilepsy. These deaths can be due to Status epilepticus, when a seizure lasts too long; an accident, where the risk was increased due to a seizure; or suicide, of which epilepsy patients are at greater risk, amongst other causes. In some cases there’s no clear reason why a patient with epilepsy has died. When this happens, it’s called sudden unexpected death in epilepsy (SUDEP). The biggest risk factor for SUDEP is having uncontrolled seizures. This can happen more frequently if a patient does not take epilepsy medications as they are advised, the medications they are taking are not fully effective in controlling their seizures, and/or around when a patient is switching from one medication to another. Accurately determining the cause of death in patients with epilepsy is important if you wish to monitor the health of epileptic patients particularly in relation to the use of antiepileptic medications. The purpose of this analysis is to explore how causes of deaths related to epilepsy are recorded by the GP and in death registration data to inform potential analyses within a national antiepileptics registry. The registry is helping to benefit the health of patients in England by enabling the monitoring of the use of antiepileptics in relation to measures introduced to ensure their safe use in women of child bearing potential.
Sudden unexpected death in epilepsy (SUDEP) is defined as death in a patient with epilepsy that is not due to trauma, drowning, status epilepticus, or other known causes but for which there is often evidence of an associated seizure. As SUDEP is often unwitnessed, diagnosis is typically made through a post-mortem. Cause of death data for individual patients is predominantly available through death registrations databases. However, in England these are currently coded using the International Classification of Diseases (ICD-10) hierarchy which does not have a specific code for SUDEP. Cause of death can also be recorded by a GP following notification of autopsy results. The Systematized Nomenclature of Medicine Clinical Terms (SNOMED) coding system, often used for this, does contain a specific code for SUDEP. The purpose of this analysis is to explore the coding of causes of death related to epilepsy in linked primary care and Office for National Statistics (ONS) death registrations data in order to inform potential analyses of SUDEP using death registrations data alone linked to the England Antiepileptics in Pregnancy Registry developed by the Medicines and Healthcare products Regulatory Agency (MHRA) and National Health Service (NHS) Digital. Such analyses will help monitor the impact of changes in the use of antiepileptics over time, particularly valproate and topiramate which are targets for risk minimisation and inform future regulatory and public health policy. Patients with an epilepsy-related code recorded as a cause of death in either the primary care or ONS death registrations data will be included in the study. The patterns of causes of death recorded within the death registrations data will be cross tabulated with recorded causes of death in the primary care data with percentage used to describe the distribution of one in relation to the other.
Death related to epilepsy; death related to epilepsy due to status epilepticus, an accident, suicide, SUDEP, or other
Katherine Donegan - Chief Investigator - MHRA
Katherine Donegan - Corresponding Applicant - MHRA
Helen Booth - Collaborator - CPRD
Sophie Scanlon - Collaborator - MHRA
ONS Death Registration Data