title: Combined analysis of risk factors for SUDEP.
abstract: OBJECTIVE
  To pool data from four published case-control studies of sudden unexpected death in epilepsy (SUDEP) with live controls, to increase the power to determine risk factors.
  
  
  METHODS
  Case-control studies from the United States, Sweden, Scotland, and England were combined. SUDEP was defined as (1) a history of epilepsy (>1 epileptic seizure during a period of < 5 years); (2) death occurring suddenly; (3) death unexpected (i.e., no life-threatening illness); and (4) death remained unexplained after all investigative efforts, including autopsy. Definite SUDEP required all criteria. Logistic regression analyses adjusted for study. Further analysis simultaneously adjusted for study, age at death, gender, and duration of epilepsy.
  
  
  RESULTS
  Of the risk factors that could be analyzed across some or all studies, those that were statistically significant were increased frequency of generalized tonic-clonic seizures (GTCS), use of polytherapy, duration of epilepsy, young age at onset, gender, symptomatic etiology, and lamotrigine therapy. Results persisted when epilepsy onset was younger than 16 years and when it was 16 years or older. In univariate analysis, lamotrigine therapy was associated with significantly increased risk for SUDEP among individuals with idiopathic generalized epilepsy.
  
  
  CONCLUSIONS
  This analysis refines the identification of people with epilepsy that are at particular risk of SUDEP. The emerging profile indicates that people with early onset refractory symptomatic epilepsy with frequent GTCS and antiepileptic drug (AED) polytherapy are at higher risk. The results suggest that reduction of the number of GTCS is a priority, of more importance than reducing the number of AEDs. The role of AEDs and other treatment should be analyzed further in future studies.
authors.affiliation: Columbia University, New York, New York, USA. dch5@columbia.edu
authors.forename: Dale C
authors.initials: DC
authors.lastname: Hesdorffer
authors.forename: Torbjorn
authors.initials: T
authors.lastname: Tomson
authors.forename: Emma
authors.initials: E
authors.lastname: Benn
authors.forename: Josemir W
authors.initials: JW
authors.lastname: Sander
authors.forename: Lena
authors.initials: L
authors.lastname: Nilsson
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Langan
authors.forename: Thaddeus S
authors.initials: TS
authors.lastname: Walczak
authors.forename: Ettore
authors.initials: E
authors.lastname: Beghi
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Brodie
authors.forename: Allen
authors.initials: A
authors.lastname: Hauser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use; D016022:Case-Control Studies; D015331:Cohort Studies; D003645:Death, Sudden / Q000453:epidemiology*; D004739:England / Q000453:epidemiology; D004827:Epilepsy / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000927:Anticonvulsants