Utilization of elective hip and knee arthroplasty by age and payer.

Elective joint arthroplasty improves the quality of life for patients with severe arthritis. In the United States, utilization of services varies with insurance status. We asked the following questions: (1) Is there an increase in the utilization of elective hip and knee arthroplasty after age 65? (2) Does the difference in utilization between the insured and general populations decrease at age 65 (the age at which Medicare provides near universal coverage)? (3) Does Medicare become the primary payer of elective hip and knee arthroplasty after the age of 65? We used the National Inpatient Sample to identify patients and payers of elective hip and knee arthroplasties by age. We analyzed these data using regression models. At age 65, there was an upward shift in the incidence of arthroplasties in the general and the insured populations and the difference between these two populations decreased. Medicare was the primary payer for the majority of arthroplasties after age 65. We conclude at age 65 the following occurs: (1) utilization of elective joint arthroplasty increases; (2) the difference between the insured population and the general population decreases; and (3) Medicare becomes the primary payer of arthroplasties.