title: Rupture rate for patients with untreated unruptured intracranial aneurysms in South Korea during 2006-2009.
abstract: OBJECTIVE
  The authors investigated the rupture rate among patients with untreated unruptured intracranial aneurysms (UIAs) in South Korea during 2006-2009.
  
  
  METHODS
  A longitudinal study using national representative health-claim data, including all hospital records for every Korean citizen, was used. Patients with a UIA who were 18-80 years old in 2006 were identified using the I67.1 ICD-10 code. To select eligible patients, a historical period of 1 year prior to the first diagnosis of a UIA in 2006 was utilized. Patients with a previous UIA diagnosis, subarachnoid hemorrhage (SAH), or treatments, such as clipping or coiling, during the historical period were excluded from analysis. Patients with head trauma or a brain tumor during the historical period were also excluded. Eligible patients were followed up for at least 3 years from the index date. Rupture was defined as SAH events with at least 14 days of hospitalization, using the I60 ICD-10 code and excluding the I60.8 code, or death within 14 days of hospitalization.
  
  
  RESULTS
  Seven thousand four hundred four patients with UIAs were identified, including 1441 treated patients (20%) and 5963 untreated patients (80%), with a median follow-up of 3.3 years. Rupture events occurred in 163 (0.9 cases/100 person-years) of the 5963 untreated patients. The rupture rate was highest in the 1st year after UIA diagnosis. An older age was a risk factor for rupture among patients with UIAs.
  
  
  CONCLUSIONS
  The overview of the incidence of rupture indicates the need for a preventive strategy and future studies to prevent rupture in Asian patients with UIAs.
authors.affiliation: National Evidence-based Healthcare Collaborating Agency, Seoul, Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Min Kyung
authors.initials: MK
authors.lastname: Hyun
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Na Rae
authors.initials: NR
authors.lastname: Lee
authors.forename: Jin Seub
authors.initials: JS
authors.lastname: Hwang
authors.forename: Jin-Won
authors.initials: JW
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D002532:Intracranial Aneurysm / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology; D055815:Young Adult