Cohort Definition Name : Earliest event of Epilepsy
Contributor name : Azza Shoaibi’
Contributor OrcId : 0000-0002-6976-2594’
Logic Description : Earliest occurrence of Epilepsy indexed on diagnosis date cohort exit is the end of continuous observation.
Recommended study application : target or outcome
Assertion statement : This cohort definition was executed on at least one real person-level observational health data source and resulted in a cohort with at least 1 person.
Target Clinical Description : A seizure is a transient occurrence of signs or symptoms, ranging from apparent convulsions to unobservable experiential phenomena, primarily caused by abnormal brain neuronal activity. Epilepsy (also seizure disorder) describes a condition in which a person has a risk of recurrent seizures due to a chronic, underlying process related to brain abnormality. Epilepsy can occur throughout life and is more common among younger and older people. Using the definition of epilepsy as two or more unprovoked[1] seizures more than 24 hours apart, the incidence of epilepsy is 30-50 per 100,000 people in high-income countries, and the prevalence estimates are 4-10 per 1000. These disease burden estimates in low or middle-income countries are approximately two times higher. The etiology may include genetic factors, anatomical anomalies, fever, metabolic disorders, substance or medication use, traumatic brain injury, infections, stroke, and neurodegenerative diseases.
"Evaluation conclusion : We performed the evaluation across a network of claim data sources and 1 EHR US data source. The data sources are:
IBM® MarketScan® Commercial Database (CCAE), Optum’s longitudinal EHR repository (Optum EHR), Optum’s Clinformatics® Data Mart (DOD), IBM® MarketScan® Multi-State Medicaid Database (MDCD), IBM® MarketScan® Medicare Supplemental Database (MDCR), Japan Claims Database (JMDC), Clinical Practice Research Datalink (CPRD) , IQVIA® Australia Longitudinal Patient Data (LPD) database (Australia), IQVIA® Disease Analyzer (DA) France database (France), QVIA® Disease Analyzer (DA) Germany database (Germany), IQVIA® Adjudicated Health Plan Claims Data (formerly PharMetrics Plus) - US database (PharMetrics), IQVIA® Ambulatory EMR (EMR).
The algorithm retrieves subjects from 11 databases tested. Several more specific cohorts requiring varying combinations of inclusion criteria such at least one additional diagnosis code within 90 or 365 days of index date, use of antiepileptic drugs, and 2-year epilepsy free washout were also considered, given the possibility of the single-code incident cohort including some rule-out diagnoses. Using the more specific cohorts only slightly improves the specificity and PPV of the algorithm albeit at the expense of sensitivity as determined by Phevaluator . It should be noted that there is a drastic reduction in sensitivity when using any of the more specific cohorts, with the except of one cohort that has an inclusion criteria of one additional diagnosis or a drug exposure to antiepileptics within a year of index.
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