title: The incidence of stroke by socioeconomic status, age, sex, and stroke subtype: a nationwide study in Korea.
abstract: OBJECTIVE
  To date, studies have not comprehensively demonstrated the relationship between stroke incidence and socioeconomic status. This study investigated stroke incidence by household income level in conjunction with age, sex, and stroke subtype in Korea.
  
  
  METHODS
  Contributions by the head of household were used as the basis for income levels. Household income levels for 21 766 036 people were classified into 6 groups. The stroke incidences were calculated by household income level, both overall within income categories and further by age group, sex, and stroke subtype. To present the inequalities among the six ranked groups in a single value, the slope index of inequality and relative index of inequality were calculated.
  
  
  RESULTS
  In 2005, 57 690 people were first-time stroke patients. The incidences of total stroke for males and females increased as the income level decreased. The incidences of stroke increased as the income level decreased in those 74 years old and under, whereas there was no difference by income levels in those 75 and over. Intracerebral hemorrhage for the males represented the highest inequality among stroke subtypes. Incidences of subarachnoid hemorrhage did not differ by income levels.
  
  
  CONCLUSIONS
  The incidence of stroke increases as the income level decreases, but it differs according to sex, age, and stroke subtype. The difference in the relative incidence is large for male intracerebral hemorrhage, whereas the difference in the absolute incidence is large for male ischemic stroke.
authors.affiliation: Graduate School of Public Health, Seoul National University, Seoul, Korea. ; Health Insurance Policy Research Institute, National Health Insurance Service, Seoul, Korea.
authors.forename: Su Ra
authors.initials: SR
authors.lastname: Seo
authors.affiliation: Department of Preventive Medicine, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Su Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Health Policy and Management, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Sang-Yi
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Busan National University School of Medicine, Busan, Korea.
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Yoon
authors.affiliation: Department of Health Policy and Management, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Hyung-Geun
authors.initials: HG
authors.lastname: Park
authors.affiliation: Graduate School of Public Health, Seoul National University, Seoul, Korea.
authors.forename: Seung Eun
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Chungnam National University School of Medicine, Research Institute for Medical Sciences, Daejeon, Korea.
authors.forename: Chul-Woung
authors.initials: CW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D007182:Income / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea; D012737:Sex Factors; D012923:Social Class; D020521:Stroke / Q000145:classification / Q000453:epidemiology* / Q000523:psychology
keywords: Incidence; Income class; Republic of Korea; Stroke
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