title: Psychiatric disorders and mortality among people in homeless shelters in Denmark: a nationwide register-based cohort study.
abstract: BACKGROUND
  The increased mortality of homeless people compared with non-homeless people might be linked to psychiatric disorders. However, homeless people are, because of their insufficient accommodation, difficult to sample and monitor, which has limited previous studies. We aimed to assess registered psychiatric disorders, mortality, and predictors of mortality in the homeless shelter population in Denmark.
  
  
  METHODS
  We did a nationwide, prospective, register-based cohort study of homeless people aged 16 years and older who were registered in the Danish Homeless Register between Jan 1, 1999, and Dec 31, 2009. We calculated the proportion of registered psychiatric disorders, overall and cause-specific standardised mortality ratio (SMR), and life expectancy. Hazard ratios (HRs) were used to assess predictors of death.
  
  
  RESULTS
  32,711 homeless people (23,040 men and 9671 women) were included in the study population. 14,381 men (62·4%) and 5632 women (58·2%) had registered psychiatric disorders, and 11,286 men (49·0%) and 3564 women (36·9%) had a substance abuse diagnosis. During the study period, 3839 men (16·7%) and 951 women (9·8%) died. The overall SMR for men was 5·6 (95% CI 5·4-5·8) and for women was 6·7 (6·2-7·1), and external causes accounted for 1161 (27·9%) of 4161 deaths for which information on the cause was available. Remaining life expectancy at age 15-24 years was 21·6 years (95% CI 21·2-22·1) and 17·4 years (16·4-18·5) lower for homeless men and women, respectively, than the general population. Registered substance abuse disorder was associated with the highest mortality risk compared with no psychiatric contact registered (adjusted HR 1·4, 95% CI 1·3-1·5 for men; 1·7, 1·4-2·1 for women).
  
  
  CONCLUSIONS
  Health problems are extensive in the homeless shelter population and there is an urgent need for more sustained efforts to reduce the high morbidity and mortality, especially from external causes. Register data is an important resource to supplement existing knowledge on homeless people with more valid and detailed information.
  
  
  BACKGROUND
  The Danish Council for Independent Research.
authors.affiliation: Mental Health Centre Copenhagen and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. frkfeodor@hotmail.com
authors.forename: Sandra Feodor
authors.initials: SF
authors.lastname: Nielsen
authors.forename: Carsten Rygaard
authors.initials: CR
authors.lastname: Hjorthøj
authors.forename: Annette
authors.initials: A
authors.lastname: Erlangsen
authors.forename: Merete
authors.initials: M
authors.lastname: Nordentoft
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D002423:Cause of Death; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D006703:Ill-Housed Persons / Q000706:statistics & numerical data*; D018453:Homeless Youth / Q000706:statistics & numerical data; D006798:Housing / Q000706:statistics & numerical data*; D006801:Humans; D008017:Life Expectancy; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012016:Reference Values; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D016019:Survival Analysis; D055815:Young Adult