Presentation: Cost-Effectiveness of Total Knee Replacement (TKR) in the US: Impact of Patient Risk and Hospital Volume (2007)

84 Cost-Effectiveness of Total Knee Replacement (TKR) in the US: Impact of Patient Risk and Hospital Volume

BACKGROUND: Total knee replacement (TKR) is frequently performed to relieve pain and improve quality of life for persons with end-stage knee arthritis. The annual volume of TKR in the US exceeds 400,000. The cost-effectiveness of TKR in the US has not been examined carefully, nor have the economic consequences of hospital volume and individual perioperative risk.
OBJECTIVE: To estimate cost-effectiveness of TKR for low- and high-risk patients with end-stage knee arthritis and to examine whether hospital volume influences cost-effectiveness assessments.
METHODS: We developed a Markov state-transition computer simulation model of treatment options for end-stage knee arthritis. We conducted analyses for the overall population of US patients with end stage knee arthritis and three sub-populations: low, medium and high risk. Patient risk was defined based on the likelihood of perioperative complications. We considered four competing strategies for each group: no TKR and undergoing TKR in low-, medium-, and high-volume centers. Perioperative and longer-term outcomes of TKR were derived from Medicare claims and survey data from a national cohort of TKR recipients. Costs were derived from NHANES data, published literature and Medicare reimbursement schedules and expresseed in 2004 $US. Outcomes included quality-adjusted life expectancy, lifetime costs and cost-effectiveness ratios. Analysis was conducted from a societal perspective, using 3% annual discount rates. We performed a wide range of sensitivity analyses to identify parameters affecting cost-effectiveness.
RESULTS: In the general population (mean age 73 years), TKR increased life expectancy from 4.2 to 6.7 quality-adjusted life-years (QALY) with lifetime costs increasing from $29,000 (no TKR) to $42,500 after TKR. The resulting cost-effectiveness ratio was $5,320/QALY. In the worst-case scenario (high risk patients receiving TKR in a low volume center) the cost-effectiveness ratio was $10,900/QALY. TKR in low-volume centers was a dominated strategy (higher cost, lower effectiveness) compared to having TKR in higher-volume centers. Results were most sensitive to improvement in quality of life after successful TKR, cost of TKR and cost of living with end-stage knee arthritis.
CONCLUSIONS: For persons with end-stage knee arthritis TKR is very cost-effective, even for high-risk patients and patients who undergo TKR in low-volume centers. The cost-effectiveness of TKR is comparable to the cost-effectivenss of ACL reconstruction, lumbar discectomy and total hip replacement, and lies well below established willingness-to-pay thresholds in the US.

 E. Losina, None; C.L. Kessler, None; R.P. Walensky, None; P.S. Emrani, None; W.M. Reichmann, None; E.A. Wright, None; D.H. Solomon, None; A.D. Paltiel, None; E. Yelin, None; J.N. Katz, None.