title: Contribution of psychiatric illness and substance abuse to 30-day readmission risk.
abstract: BACKGROUND
  Little is known about the contribution of psychiatric illness to medical 30-day readmission risk.
  
  
  OBJECTIVE
  To determine the independent contribution of psychiatric illness and substance abuse to all-cause and potentially avoidable 30-day readmissions in medical patients.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Patients discharged from the medicine services at a large teaching hospital from July 1, 2009 to June 30, 2010.
  
  
  METHODS
  The main outcome of interest was 30-day all-cause and potentially avoidable readmissions; the latter determined by a validated algorithm (SQLape) in both bivariate and multivariate analysis. Readmissions were captured at 3 hospitals where the majority of these patients are readmitted.
  
  
  RESULTS
  Of 6987 discharged patients, 1260 were readmitted within 30 days (18.0%); 388 readmissions were potentially avoidable (5.6%). In multivariate analysis, 2 or more prescribed outpatient psychiatric medications (odds ratio [OR]: 1.1, 95% confidence interval [CI]: 1.01-1.20) or any prescription of anxiolytics (OR: 1.16, 95% CI: 1.00-1.35) were associated with increased all-cause readmissions, whereas discharge diagnoses of anxiety (OR: 0.82, 95% CI: 0.68-0.99) or substance abuse (OR: 0.80, 96% CI: 0.65-0.99) were associated with fewer all-cause readmissions. These findings were not replicated as predictors of potentially avoidable readmissions; rather, patients with discharge diagnoses of depression (OR: 1.49, 95% CI: 1.09-2.04) and schizophrenia (OR: 2.63, 95% CI: 1.13-6.13) were at highest risk.
  
  
  CONCLUSIONS
  Our data suggest that patients treated during a hospitalization for depression and for schizophrenia are at higher risk for potentially avoidable 30-day readmissions, whereas those prescribed more psychiatric medications as outpatients are at increased risk for all-cause readmissions. These populations may represent fruitful targets for interventions to reduce readmission risk.
authors.affiliation: Hospital Medicine Section, Department of Veterans Affairs Medical Center, Eastern Colorado Health Care System, Denver, CO 80220, USA. Robert.Burke5@va.gov
authors.forename: Robert E
authors.initials: RE
authors.lastname: Burke
authors.forename: Jacques
authors.initials: J
authors.lastname: Donzé
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Schnipper
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D017831:Diagnosis, Dual (Psychiatry) / Q000523:psychology / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D008875:Middle Aged; D010359:Patient Readmission / Q000639:trends*; D012189:Retrospective Studies; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D013997:Time Factors