title: Hospital readmissions after primary shoulder arthroplasty.
abstract: BACKGROUND
  Although shoulder arthroplasty procedures are more frequently performed in the United States, there is insufficient information on outcome measures such as hospital readmission rates or factors for readmission after surgery.
  
  
  METHODS
  The State Inpatient Database from 7 different states was used to identify patients who underwent hemiarthroplasty, total shoulder arthroplasty (TSA), or reverse total shoulder arthroplasty (RTSA) from 2005 through 2010. The database was used to determine the 90-day readmission rate, causes of readmission, and risk factors for readmission. Multivariate modeling and a Cox proportional hazards model were used to measure factors and risk for readmission.
  
  
  RESULTS
  Included were 26,218 patients receiving shoulder arthroplasty, with an overall 90-day readmission rate of 7.3%. RTSA had the highest rate (11.2%), followed by hemiarthroplasty (8.2%) and TSA (6.0%; P < .001). Medical complications contributed to 82% of readmissions, and surgical complications contributed to 18%. Osteoarthritis was the most common medical diagnosis (11%), followed by deep venous thrombosis or pulmonary embolism (4.4%) and pneumonia (3.9%). Infection was the most common surgical cause of readmission (4.8%), followed by dislocation (4.6%). There was a stepwise increase in risk of readmission with increasing age. Patients with Medicaid insurance had more than a 50% greater risk of readmission than patients with Medicare. Procedures performed at medium-volume and high-volume hospitals showed lower risk of readmission than low-volume centers.
  
  
  CONCLUSIONS
  Patients undergoing RTSA had higher hospital readmission rates than those undergoing hemiarthroplasty or TSA, but most readmissions after shoulder arthroplasty were due to medical causes.
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: William W
authors.initials: WW
authors.lastname: Schairer
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA. Electronic address: FeeleyB@orthosurg.ucsf.edu.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Feeley
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000453:epidemiology / Q000601:surgery*; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D017006:Rotator Cuff / Q000601:surgery; D012785:Shoulder Joint / Q000601:surgery*; D014481:United States / Q000453:epidemiology
keywords: Shoulder arthroplasty; complications; hospital readmission; outcomes