title: Is low individual socioeconomic status (SES) in high-SES areas the same as low individual SES in low-SES areas: a 10-year follow-up schizophrenia study.
abstract: OBJECTIVE
  This study investigates the relationship between individual and neighborhood socioeconomic status (SES) and mortality among patients with schizophrenia.
  
  
  METHODS
  A study population was identified from the National Health Insurance Research Database (NHIRD) prior to the end of 1999 that included 60,402 patients with schizophrenia. Each patient was tracked until death or to the end of 2009. Individual SESs were defined by enrollee category. Neighborhood SES was defined by enrollee category (as a proxy for occupation) and education, which were classified according to the conventions of Hollingshead. Neighborhoods were also grouped into advantaged and disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rate between the different SES groups after adjusting for possible confounding factors and risk factors.
  
  
  RESULTS
  During the 10-year follow-up period, the mortality rates among high, moderate, and low individual SES groups were 12.22, 14.75, and 18.48%, respectively (P < 0.001). Schizophrenia patients with low individual SESs in disadvantaged neighborhoods had a risk of death that was 18-22% higher than that of those with high individual SES in advantaged neighborhoods. The analysis of the combined effect of individual SES and neighborhood SES revealed that the death rates were highest among those with low individual SES and low neighborhood SES (P < 0.001).
  
  
  CONCLUSIONS
  Schizophrenia patients with low individual SES in disadvantaged neighborhoods have the highest risk of mortality despite a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.
authors.affiliation: Department of Community Psychiatry, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital, 130, Kai-Syuan 2nd Rd, Lingya District, Kaohsiung City, Taiwan.
authors.forename: Kuan-Yi
authors.initials: KY
authors.lastname: Tsai
authors.forename: Tieh-Chi
authors.initials: TC
authors.lastname: Chung
authors.forename: Ching-Chih
authors.initials: CC
authors.lastname: Lee
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Chou
authors.forename: Chao-Yueh
authors.initials: CY
authors.lastname: Su
authors.forename: Shih-Pei
authors.initials: SP
authors.lastname: Shen
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.forename: Frank Huang-Chih
authors.initials: FH
authors.lastname: Chou
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models; D012111:Residence Characteristics; D012307:Risk Factors; D012559:Schizophrenia / Q000401:mortality*; D012565:Schizophrenic Psychology; D012923:Social Class; D012959:Socioeconomic Factors; D015996:Survival Rate; D013624:Taiwan