Evidence of Pent-Up Demand for Total Hip and Total Knee Arthroplasty at Age 65

Background

Despite efforts to curtail the economic burden of total joint arthroplasty (TJA), utilization of these successful procedures continues to increase. Previous studies have provided evidence for pent-up demand (delaying necessary medical care until financially feasible) in health care as insurance status changes. We sought to determine whether evidence exists for pent-up demand in the TJA population when patients become eligible for Medicare enrollment.

Methods

The 2014 Nationwide Readmission Database was used to determine the incidence of TJA. The observed increase in incidence from age 64 to 65 was compared to the expected increase. Pent-up demand was calculated by subtracting the expected from the observed difference in frequency of TJA, and excess cost was determined by multiplying this value by the median cost of a primary TJA. The Medicare Expenditure Panel Survey Household Component was used to compare out-of-pocket (OOP) costs, access to care, and insurance coverage among patients aged 60-64 (group 1) and 66-70 (group 2).

Results

The expected and observed increases in TJA procedures from age 64 to 65 were 595 and 5211, respectively, resulting in pent-up demand of 4616 joint arthroplasties (1273 THA and 3343 TKA), and an excess cost of $55 million (range, $33 million-$70 million). Mean total OOP expenses for patients in group 1 were significantly greater ($1578.39) than patients in group 2 ($1143.63, P < .001). Despite spending more money OOP, the proportion of patients who were unable to obtain necessary medical care was significantly higher in group 1 than group 2 (4.9% vs 2.4%, P < .0001). This discrepancy was most prominent among patients with public insurance (10.6% vs 2.5%, P < .0001).

Conclusion

The findings of this study suggest that patients with hip and knee osteoarthritis likely delay elective TJA until they are eligible for Medicare enrollment, resulting in significant additional financial burden to the public health system. As the population ages, it will become increasingly important for stakeholders and policy-makers to be aware of this pent-up demand for TJA procedures.

Level of Evidence

Therapeutic level IV.