Cost-effectiveness of total knee arthroplasty in the United States: patient risk and hospital volume.
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.
Losina
Elena
E
Department of Orthopedic Surgery, Orthopedic and Arthritis Center for Outcomes Research, Brigham and Women's Hospital, Boston, MA 02115, USA. elosina@partners.org
Walensky
Rochelle P
RP
Kessler
Courtenay L
CL
Emrani
Parastu S
PS
Reichmann
William M
WM
Wright
Elizabeth A
EA
Holt
Holly L
HL
Solomon
Daniel H
DH
Yelin
Edward
E
Paltiel
A David
AD
Katz
Jeffrey N
JN
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