People with epilepsy sometimes experience difficulty controlling their conditions with medications and still experience seizures, which are called drug-resistant epilepsy (DRE). People with DRE have been shown to have a higher risk of physical injuries, mental illness and mortality compared to people whose epilepsy is well controlled with medications. There is limited information on how many people with epilepsy have DRE in the United Kingdom and the characteristics of these people.
The present study aims to better understand patient characteristics, underlying conditions, and death among a cohort of people diagnosed with epilepsy who received at least three anti-seizure medications. Data from the Clinical Practice Research Datalink will be used for this study to provide up-to-date real-world information for this patient group and to better understand the impact of their condition on their risk of death, in order to help improve the care of these people.
Anti-seizure medications (ASMs) are the mainstay of treatment for epilepsy. However, as many as 30-40% of people continue to experience recurrent epileptic seizures and are diagnosed as having drug-resistant epilepsy (DRE). People with DRE have increased risks of physical injury, mental illness, and mortality.
This retrospective, non-interventional cohort study will use data from the Clinical Practice Research Datalink (CPRD) to (1) quantify DRE among people with epilepsy in the UK; (2) describe characteristics and comorbidities; and (3) assess the all-cause and epilepsy-related mortality among people with DRE. The study population will be people who had a diagnosis of epilepsy and developed DRE in the UK. Based on the International League against Epilepsy (ILAE) criteria, an epileptic patient who started a third ASM (as monotherapy or combination therapy) will be defined as having DRE. The third ASM is deemed as the primary exposure in the study.
The point-prevalence of DRE will be estimated on 1 January by dividing the number of patients with DRE by the total number of patients with epilepsy for each calendar year. Descriptive analyses will be summarised as frequencies and percentages for categorical characteristics (age categories, gender, socio-economic status, comorbidities) as well as means, standard deviations, medians, interquartile ranges, and ranges for continuous characteristics (age, time from epilepsy diagnosis to DRE). All-cause and epilepsy-related mortality rates will be estimated for each calendar year. Standardised mortality rate ratioss will be derived by dividing the crude rates by the national mortality rates.
The public health benefit intended by this study is to provide up-to-date epidemiological evidence on people with DRE in the UK, which may be used by clinicians, researchers, and policy makers to better characterise the unmet need in this patient population and help improve the management of care for those people within the National Health Service.
The following outcomes will be evaluated:
• Point-prevalence of DRE (Objective 1): annual prevalence during study period
• Baseline patient characteristics and comorbidities (Objective 2):
o Age at first recorded DRE diagnosis in years and by decade
o Gender
o Charlson Comorbidity Index
o Other comorbidities: top 10 recorded diagnoses in CPRD
o Proportion of patients with DRE per geographical region
o Time from epilepsy diagnosis to DRE diagnosis
• Mortality (Objective 3)
o Overall
o Epilepsy-related
Craig Currie - Chief Investigator - Pharmatelligence Limited t/a Human Data Sciences
Ellen Hubbuck - Corresponding Applicant - Pharmatelligence Limited t/a Human Data Sciences
Bronwyn Do Rego - Collaborator - LivaNova
Debra Gregory - Collaborator - Harvey Walsh Ltd
Francesca Barion - Collaborator - LivaNova
Lara Groves - Collaborator - OPEN Health Group
Oliver Williams - Collaborator - LivaNova
Reginald Lassagne - Collaborator - LivaNova
Rohit Shankar - Collaborator - Cornwall Partnership NHS Foundation Trust
Teresa Carroll - Collaborator - OPEN Health Group
Vanessa Danielson - Collaborator - Not from an Organisation
Xiaocong Marston - Collaborator - Harvey Walsh Ltd
Debra Gregory - Collaborator - Harvey Walsh Ltd
Joanna Murphy - Collaborator - LivaNova
Myriam Alexander - Collaborator - Harvey Walsh Ltd
Oliver Williams - Collaborator - LivaNova
Sue Beecroft - Collaborator - Harvey Walsh Ltd
Teresa Carroll - Collaborator - OPEN Health Group
ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation