Abstract
Significance
Increasing health care costs are bankrupting the United States and other industrialized countries. To control and/or reduce costs in health care, hospitals, payers, and patients are turning to evidence-based meta-analyses and health economic analyses to identify medical treatments that provide value (value=outcome/cost). Objective: To determine if clinical outcome (patient reported outcomes) analyses or value/economic analyses are more likely to provide the evidence needed for adoption of new technologies in arthroplasty.
Methods
A proprietary joint arthroplasty database of patient reported outcomes (PROs) was analyzed to determine the minimum clinically important differences (MCIDs) for PROs used for total knee replacement surgery. The PROs analyzed were: (1) European quality of life (EQ-5D); Oxford Knee Score (OKS); (3) Lower Extremity Activity Scale (LEAS); and (4) Likert Pain Scale (LPS). The MCID was calculated using a distribution method where the MCID equals one half the standard deviation of the score change, MCID = σΔ/2. For clinical meta-analyses, new technologies must demonstrate statistically significant better PROs and the difference must be greater than the MCID. For economic analyses, quality adjusted life years (QALYs) are used. For example, if a total knee replacement (TKR) improved a patient's health-related quality of life by 10% (0.10) and the assumed implant life is 15 years, the patient received 1.5 QALYs (0.10 × 15 years). If the total cost of care for the knee replacement surgery is $30,000, the cost per QALY is $20,000 ($30,000/1.5 QALYs).
Results
The MCIDs for EQ-5D, OKS, LEAS, and LPS are 0.086%, 4.6 points, 1.6 points, and 1.3 points, respectively. The mean change (one-year post-operative EQ-5D minus pre-operative EQ-5D) for health-related quality of life is 15% (0.15). The average patient received 2.25 QALYs (0.15 × 15 years) from the surgery. The average cost per QALY is $13,333. However, if a new technology improves the mean health-related quality of life by 1% and the assumed implant life is 15 years, the patient receives 0.15 QALYs of improvement. With an average cost per QALY of $13,333, the new technology will be cost effective if the new technology cost is less than or equal to $2,000 (0.15 × $13,333) per patient.
Conclusions
Achieving clinical superiority with new arthroplasty technology will be difficult because the minimum clinically important differences that need to be achieved are significant (EQ-5D 8.6%, OKS 4.6 points, LEAS 1.3 points, and LPS 1.3 points). However, small mean improvements in health-related quality of life (1%) can make the new technology cost effective. New technologies for arthroplasty surgery will increasingly need economic analyses to demonstrate cost effectiveness. Orthopaedic surgeons and manufacturers must collaborate to routinely collect health-related quality of life (EQ-5D) patient reported outcomes to provide a pathway for adoption of new innovative arthroplasty technologies.
