title: Factors Affecting Length of Stay, Readmission, and Revision After Shoulder Arthroplasty: A Population-Based Study.
abstract: BACKGROUND
  Increased length of hospital stay, hospital readmission, and revision surgery are adverse outcomes that increase the cost of elective orthopaedic procedures, such as shoulder arthroplasty. Awareness of the factors related to these adverse outcomes will help surgeons and medical centers design strategies for minimizing their occurrence and for managing their associated costs.
  
  
  METHODS
  We analyzed data from the New York Statewide Planning and Research Cooperative System on 17,311 primary shoulder arthroplasties performed from 1998 to 2011 to identify factors associated with extended lengths of hospitalization after surgery, readmission within ninety days, and surgical revision.
  
  
  RESULTS
  The factors associated with each of these three adverse outcomes were different. Longer lengths of hospital stay were associated with female sex, advanced patient age, Medicaid insurance, comorbidities, fracture as the diagnosis for arthroplasty, higher hospital case volumes, and lower surgeon case volumes. Readmission was associated with advanced patient age and medical comorbidities. The most common diagnoses for readmission within ninety days were fluid and electrolyte imbalance (28%), acute pulmonary problems (21%), cardiac arrhythmia (20%), heart failure (15%), acute myocardial infarction (10%), and urinary tract infection (10%). Revision was associated with younger patient age and osteoarthritis or traumatic arthritis. The most common diagnoses at the time of revision surgery were unspecified mechanical complications of the implant (60%), shoulder pain (18%), dislocation of the prosthetic joint (12%), component loosening (10%), a broken prosthesis (8%), a cuff tear (7%), and infection (7%).
  
  
  CONCLUSIONS
  A small number of easily identified characteristics (sex, age, race, insurance type, comorbidities, diagnosis, and provider case volumes) were significantly associated with longer lengths of stay, readmission, and revision surgery. Consideration of these factors and their effects may guide efforts to improve patient safety and to manage the costs associated with these adverse outcomes.
authors.affiliation: Shoulder and Elbow Surgery Service, University of Washington Medical Center, Box 356500, Seattle, WA 98195-6500. E-mail address for F.A. Matsen: matsen@uw.edu.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Matsen
authors.affiliation: Department of Statistics, University of Washington, Box 354322, Seattle, WA 98195-4322.
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Statistics, University of Washington, Box 354322, Seattle, WA 98195-4322.
authors.forename: Huizhong
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Statistics, University of Washington, Box 354322, Seattle, WA 98195-4322.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Yuan
authors.affiliation: Shoulder and Elbow Surgery Service, University of Washington Medical Center, Box 356500, Seattle, WA 98195-6500. E-mail address for F.A. Matsen: matsen@uw.edu.
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Russ
authors.affiliation: Department of Statistics, University of Washington, Box 354322, Seattle, WA 98195-4322.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Sampson
mesh_terms: D000367:Age Factors; D001178:Arthroplasty / Q000009:adverse effects / Q000379:methods*; D003362:Cost-Benefit Analysis; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D007902:Length of Stay / Q000191:economics*; D016014:Linear Models; D008297:Male; D016017:Odds Ratio; D010147:Pain Measurement; D010359:Patient Readmission / Q000191:economics* / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology; D012086:Reoperation / Q000191:economics; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome