title: Cost-effectiveness of total knee arthroplasty in the United States: patient risk and hospital volume.
abstract: BACKGROUND
  Total knee arthroplasty (TKA) relieves pain and improves quality of life for persons with advanced knee osteoarthritis. However, to our knowledge, the cost-effectiveness of TKA and the influences of hospital volume and patient risk on TKA cost-effectiveness have not been investigated in the United States.
  
  
  METHODS
  We developed a Markov, state-transition, computer simulation model and populated it with Medicare claims data and cost and outcomes data from national and multinational sources. We projected lifetime costs and quality-adjusted life expectancy (QALE) for different risk populations and varied TKA intervention and hospital volume. Cost-effectiveness of TKA was estimated across all patient risk and hospital volume permutations. Finally, we conducted sensitivity analyses to determine various parameters' influences on cost-effectiveness.
  
  
  RESULTS
  Overall, TKA increased QALE from 6.822 to 7.957 quality-adjusted life years (QALYs). Lifetime costs rose from $37,100 (no TKA) to $57 900 after TKA, resulting in an incremental cost-effectiveness ratio of $18,300 per QALY. For high-risk patients, TKA increased QALE from 5.713 to 6.594 QALY, yielding a cost-effectiveness ratio of $28,100 per QALY. At all risk levels, TKA was more costly and less effective in low-volume centers than in high-volume centers. Results were insensitive to variations of key input parameters within policy-relevant, clinically plausible ranges. The greatest variations were seen for the quality of life gain after TKA and the cost of TKA.
  
  
  CONCLUSIONS
  Total knee arthroplasty appears to be cost-effective in the US Medicare-aged population, as currently practiced across all risk groups. Policy decisions should be made on the basis of available local options for TKA. However, when a high-volume hospital is available, TKAs performed in a high-volume hospital confer even greater value per dollar spent than TKAs performed in low-volume centers.
authors: Department of Orthopedic Surgery, Orthopedic and Arthritis Center for Outcomes Research, Brigham and Women's Hospital, Boston, MA 02115, USA. elosina@partners.org
authors: Elena
authors: E
authors: Losina
authors: Rochelle P
authors: RP
authors: Walensky
authors: Courtenay L
authors: CL
authors: Kessler
authors: Parastu S
authors: PS
authors: Emrani
authors: William M
authors: WM
authors: Reichmann
authors: Elizabeth A
authors: EA
authors: Wright
authors: Holly L
authors: HL
authors: Holt
authors: Daniel H
authors: DH
authors: Solomon
authors: Edward
authors: E
authors: Yelin
authors: A David
authors: AD
authors: Paltiel
authors: Jeffrey N
authors: JN
authors: Katz
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000191:economics* / Q000706:statistics & numerical data*; D003362:Cost-Benefit Analysis; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D020370:Osteoarthritis, Knee / Q000191:economics / Q000601:surgery*; D012307:Risk Factors; D014481:United States