title: Neuropsychiatric disorders and potentially preventable hospitalizations in a prospective cohort study of older Americans.
abstract: BACKGROUND
  The relative contributions of depression, cognitive impairment without dementia (CIND), and dementia to the risk of potentially preventable hospitalizations in older adults are not well understood.
  
  
  OBJECTIVE
  To determine if depression, CIND, and/or dementia are each independently associated with hospitalizations for ambulatory care-sensitive conditions (ACSCs) and rehospitalizations within 30 days after hospitalization for pneumonia, congestive heart failure (CHF), or myocardial infarction (MI).
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Population-based sample of 7,031 Americans > 50 years old participating in the Health and Retirement Study (1998-2008).
  
  
  METHODS
  The eight-item Center for Epidemiologic Studies Depression Scale and/or International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) depression diagnoses were used to identify baseline depression. The Modified Telephone Interview for Cognitive Status and/or ICD-9-CM dementia diagnoses were used to identify baseline CIND or dementia. Primary outcomes were time to hospitalization for an ACSC and presence of a hospitalization within 30 days after hospitalization for pneumonia, CHF, or MI.
  
  
  RESULTS
  All five categories of baseline neuropsychiatric disorder status were independently associated with increased risk of hospitalization for an ACSC (depression alone: Hazard Ratio [HR]: 1.33, 95% Confidence Interval [95%CI]: 1.18, 1.52; CIND alone: HR: 1.25, 95%CI: 1.10, 1.41; dementia alone: HR: 1.32, 95%CI: 1.12, 1.55; comorbid depression and CIND: HR: 1.43, 95%CI: 1.20, 1.69; comorbid depression and dementia: HR: 1.66, 95%CI: 1.38, 2.00). Depression (Odds Ratio [OR]: 1.37, 95%CI: 1.01, 1.84), comorbid depression and CIND (OR: 1.98, 95%CI: 1.40, 2.81), or comorbid depression and dementia (OR: 1.58, 95%CI: 1.06, 2.35) were independently associated with increased odds of rehospitalization within 30 days after hospitalization for pneumonia, CHF, or MI.
  
  
  CONCLUSIONS
  Depression, CIND, and dementia are each independently associated with potentially preventable hospitalizations in older Americans. Older adults with comorbid depression and cognitive impairment represent a particularly at-risk group that could benefit from targeted interventions.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington, Box 356560, 1959 NE Pacific St, Seattle, WA, 98195, USA, ddavydo1@u.washington.edu.
authors.forename: Dimitry S
authors.initials: DS
authors.lastname: Davydow
authors.forename: Kara
authors.initials: K
authors.lastname: Zivin
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Katon
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Pontone
authors.forename: Lydia
authors.initials: L
authors.lastname: Chwastiak
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Langa
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology