According to a study published in the Archives of Internal Medicine, total knee arthroplasty (TKA) may be a cost-effective procedure for older adults with advanced osteoarthritis when compared with nonsurgical treatments. The greatest cost effectiveness was achieved in hospitals that performed more than 200 TKAs on Medicare recipients over a given year.
A team of Boston-based researchers populated a computer simulation model with Medicare claims data and cost and outcomes data from several national and international sources. They then used this model to predict the lifetime costs and quality-adjusted life expectancy (QALE) (a measure of disease burden) for patients at various risks for surgical complications who underwent TKA at facilities designated by volume of procedures performed on Medicare recipients in any given year.
Overall, having undergone a TKA increased QALE of older people with end-stage knee osteoarthritis (average age, 74 years) from 6.822 quality-adjusted life years (QALYs) to 7.957. The lifetime costs among individuals who did not undergo TKA were calculated at $37,100 compared with $57,900 per person undergoing TKA, for a cost-effectiveness ratio of $18,300 per QALY (ratio of additional costs to additional benefits). The procedure appeared to be cost-effective, regardless of patients’ risk for complications after surgery, with incremental cost-effectiveness estimates ranging from $9700 per QALY for patients in the low-risk group to $28,100 for high-risk patients. The surgery was more costly and less effective when performed in low-volume centers across all risk levels. However, the procedures performed in low-volume centers were still more cost effective than medical management alone. The key limitations of the study included the absence of published data on cost of TKA stratified by risk and disease severity, which required the research team to estimate costs based on National Health and Nutrition Examination (NHANES III) data, as well as an inability to account for patient willingness to undergo the procedure.
According to the authors, approximately 12% of adults older than 60 years of age have symptoms of knee osteoarthritis, and their direct medical costs range from an estimated $1000 to $4100 per year. Almost 500,000 TKAs were performed in the United States in 2005, at a cost exceeding $11 billion; projections indicate dramatic growth in the use of this procedure over the next 2 decades. However, concerns regarding the increasing popularity of TKA and the introduction of more expensive technologies require ongoing consideration and watchfulness regarding the incremental cost-effectiveness of these procedures.