title: Continuing care after inpatient psychiatric treatment for patients with psychiatric and substance use disorders.
abstract: OBJECTIVE
  This observational study examined the association between continuing outpatient care for a psychiatric disorder, a substance use disorder, or both and decreased risk of readmission to psychiatric care after an index episode of inpatient psychiatric treatment.
  
  
  METHODS
  Treatment records from all patients with co-occurring substance use and psychiatric disorders discharged from an inpatient psychiatric setting in the Department of Veterans Affairs (VA) between July 1, 2004, and June 30, 2005 (N=26,826), were used to determine the impact of psychiatric and substance use disorder continuing care on readmission to inpatient psychiatric treatment in the 90 days after discharge.
  
  
  RESULTS
  Over 23% (6,280 of 26,826) of patients with both a psychiatric disorder and a substance use disorder who received inpatient psychiatric treatment in the VA were readmitted for additional psychiatric care within 90 days of discharge. Survival analyses indicated that receiving continuing care for a substance use disorder (hazard ratio [HR]=.84, 95% confidence interval [CI]=.77-.92, p<.001) in the 30 days after discharge from the index episode was associated with a lower likelihood of rehospitalization. Psychiatric continuing care was not associated with risk of rehospitalization. A supplementary analysis indicated that substance use disorder continuing care was still associated with a reduced risk of rehospitalization over the 12 months after discharge, although the overall magnitude of the association was diminished (HR=.92, 95% CI=.86-.99, p=.02).
  
  
  CONCLUSIONS
  Readmission to inpatient psychiatric treatment was common for patients with co-occurring disorders, and these observational findings indicate that continuing care for a substance use disorder was associated with lower risk of early readmission.
authors.affiliation: Health Services Research and Development, Department of Veterans Affairs, 2215 Fuller Rd. (11H), Ann Arbor, MI 48105, USA. marki@umich.edu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Ilgen
authors.forename: Kirsten Unger
authors.initials: KU
authors.lastname: Hu
authors.forename: Rudolf H
authors.initials: RH
authors.lastname: Moos
authors.forename: John
authors.initials: J
authors.lastname: McKellar