title: Preexisting comorbid psychiatric conditions and mortality in nonsurgical intensive care patients.
abstract: OBJECTIVE
  To examine the effects of preexisting comorbid psychiatric conditions on mortality in a large cohort of patients admitted to a nonsurgical intensive care unit.
  
  
  METHODS
  This retrospective cohort study involved 66,672 consecutive eligible nonsurgical patients admitted to intensive care units in 129 Veterans Health Administration hospitals during 2005 and 2006. Preexisting comorbid psychiatric conditions were identified by using diagnoses from outpatient encounters in the prior year for depression, anxiety, psychosis, bipolar disorders, and posttraumatic stress disorder. Generalized estimating equations were used to adjust the risks of in hospital and 30-day mortality for demographics, comorbid medical conditions, markers of severity, and abnormal findings on laboratory tests at admission.
  
  
  RESULTS
  Comorbid psychiatric conditions were identified in 28% (n = 18 698) of patients. Patients with preexisting comorbid psychiatric conditions had lower (P < .001) unadjusted in hospital mortality (7.3% vs 8.7%) and 30-day mortality (10.0% vs 12.8%) than did patients without such conditions. After demographics, comorbid medical conditions, and severity were adjusted for, risk of in-hospital mortality among patients with comorbid psychiatric conditions was somewhat higher (odds ratio, 1.07, 95% confidence interval, 1.01-1.14; P = .02), although differences in 30-day mortality (odds ratio, 1.01, 95% confidence interval, 0.94-1.08; P = .70) were no longer significant.
  
  
  CONCLUSIONS
  Preexisting comorbid psychiatric conditions are common among intensive care patients, but after comorbid medical conditions and severity were adjusted for, preexisting comorbid psychiatric conditions were not associated with a higher risk of 30-day mortality in a large national cohort of veterans.
authors.affiliation: Iowa City VA Medical Center, 601 Highway 6 West, Mailstop 152, Iowa City, IA 52246-2208, USA. thad-abrams@uiowa.edu
authors.forename: Thad E
authors.initials: TE
authors.lastname: Abrams
authors.forename: Mary
authors.initials: M
authors.lastname: Vaughan-Sarrazin
authors.forename: Gary E
authors.initials: GE
authors.lastname: Rosenthal
mesh_terms: D000368:Aged; D015331:Cohort Studies; D015897:Comorbidity; D016638:Critical Illness / Q000453:epidemiology; D005260:Female; D017052:Hospital Mortality; D006787:Hospitals, Veterans / Q000706:statistics & numerical data; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology*; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology