title: Suicide in the oldest old: an observational study and cluster analysis.
abstract: OBJECTIVE
  The older population are at a high risk for suicide. This study sought to learn more about the characteristics of suicide in the oldest-old and to use a cluster analysis to determine if oldest-old suicide victims assort into clinically meaningful subgroups.
  
  
  METHODS
  Data were collected from a coroner's chart review of suicide victims in Toronto from 1998 to 2011. We compared two age groups (65-79 year olds, n = 335, and 80+ year olds, n = 191) and then conducted a hierarchical agglomerative cluster analysis using Ward's method to identify distinct clusters in the 80+ group.
  
  
  RESULTS
  The younger and older age groups differed according to marital status, living circumstances and pattern of stressors. The cluster analysis identified three distinct clusters in the 80+ group. Cluster 1 was the largest (n = 124) and included people who were either married or widowed who had significantly more depression and somewhat more medical health stressors. In contrast, cluster 2 (n = 50) comprised people who were almost all single and living alone with significantly less identified depression and slightly fewer medical health stressors. All members of cluster 3 (n = 17) lived in a retirement residence or nursing home, and this group had the highest rates of depression, dementia, other mental illness and past suicide attempts.
  
  
  CONCLUSIONS
  This is the first study to use the cluster analysis technique to identify meaningful subgroups among suicide victims in the oldest-old. The results reveal different patterns of suicide in the older population that may be relevant for clinical care.
authors: Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors: Mark
authors: M
authors: Sinyor
authors: Department of Psychological Medicine, Tan Tock Seng Hospital, Singapore, Singapore.
authors: Lynnette Pei Lin
authors: LP
authors: Tan
authors: Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors: Ayal
authors: A
authors: Schaffer
authors: Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors: Damien
authors: D
authors: Gallagher
authors: Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors: Kenneth
authors: K
authors: Shulman
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D003866:Depressive Disorder / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D017533:Marital Status; D009864:Ontario / Q000453:epidemiology; D012111:Residence Characteristics; D012307:Risk Factors; D012919:Social Behavior; D013405:Suicide / Q000706:statistics & numerical data*
keywords: cluster analysis; oldest old; suicide