title: Predictors of rehospitalization among elderly patients admitted to a rehabilitation hospital: the role of polypharmacy, functional status, and length of stay.
abstract: OBJECTIVE
  Rehospitalizations for elderly patients are an increasing health care burden. Nonetheless, we have limited information on unplanned rehospitalizations and the related risk factors in elderly patients admitted to in-hospital rehabilitation facilities after an acute hospitalization.
  
  
  METHODS
  In-hospital rehabilitation and aged care unit.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Elderly patients 65 years or older admitted to an in-hospital rehabilitation hospital after an acute hospitalization between January 2004 and June 2011.
  
  
  METHODS
  The rate of 30-day unplanned rehospitalization to hospitals was recorded. Risk factors for unplanned rehospitalization were evaluated at rehabilitation admission: age, comorbidity, serum albumin, number of drugs, decline in functional status, delirium, Mini Mental State Examination score, and length of stay in the acute hospital. A multivariable Cox proportional regression model was used to identify the effect of these risk factors for time to event within the 30-day follow-up.
  
  
  RESULTS
  Among 2735 patients, with a median age of 80 years (interquartile range 74-85), 98 (4%) were rehospitalized within 30 days. Independent predictors of 30-day unplanned rehospitalization were the use of 7 or more drugs (hazard ratio [HR], 3.94; 95% confidence interval, 1.62-9.54; P = .002) and a significant decline in functional status (56 points or more at the Barthel Index) compared with the month before hospital admission (HR 2.67, 95% CI: 1.35-5.27; P = .005). Additionally, a length of stay in the acute hospital of 13 days or more carried a twofold higher risk of rehospitalization (HR 2.67, 95% CI: 1.39-5.10); P = .003).
  
  
  CONCLUSIONS
  The rate of unplanned rehospitalization was low in this study. Polypharmacy, a significant worsening of functional status compared with the month before acute hospital admission, and hospital length of stay are important risk factors.
authors.affiliation: Department of Rehabilitation and Aged Care Hospital Ancelle, Cremona, Italy; Geriatric Research Group, Brescia, Italy; Center for Quality Aging, Department of Medicine, Vanderbilt University, Nashville, TN. Electronic address: morandi.alessandro@gmail.com.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Morandi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellelli
authors.forename: Eduard E
authors.initials: EE
authors.lastname: Vasilevskis
authors.forename: Renato
authors.initials: R
authors.lastname: Turco
authors.forename: Fabio
authors.initials: F
authors.lastname: Guerini
authors.forename: Tiziana
authors.initials: T
authors.lastname: Torpilliesi
authors.forename: Salvatore
authors.initials: S
authors.lastname: Speciale
authors.forename: Valeria
authors.initials: V
authors.lastname: Emiliani
authors.forename: Simona
authors.initials: S
authors.lastname: Gentile
authors.forename: John
authors.initials: J
authors.lastname: Schnelle
authors.forename: Marco
authors.initials: M
authors.lastname: Trabucchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006760:Hospitalization; D006801:Humans; D007558:Italy; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D015999:Multivariate Analysis; D010359:Patient Readmission / Q000706:statistics & numerical data*; D019338:Polypharmacy; D012047:Rehabilitation Centers; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Rehospitalization; elderly; in-hospital rehabilitation risk factors