How Does Medicare Advantage Affect TJA Outcomes?

A group of researchers from the Keck School of Medicine of the University of Southern California, Mayo Clinic, and the University of Iowa collected data regarding the connection between Medicare Advantage and total knee patient variables and outcomes.

According to this multi-center research team, the proportion of Medicare beneficiaries in a Medicare Advantage plan has risen from 18% to 34% in the last 20 years—and it is likely to continue rising. The team pulled data for patients ≥65 years of age who had primary elective total joint arthroplasty (TJA) from 2015 to 2020 (Premier Healthcare Database).

Their work, “The Rise of Medicare Advantage: Effects on Total Joint Arthroplasty Patient Care and Research,” appears in the December 21, 2022, edition of The Journal of Bone and Joint Surgery.

Co-author Nathanael D. Heckmann, M.D., an assistant professor in the Department of Orthopaedic Surgery at Keck, told OTW, “My colleagues and I were seeing that a larger and larger proportion of arthroplasty patients over time had continued to enroll in Medicare Advantage plans and realized that this trend had never fully been characterized or quantified in the arthroplasty literature.”

The researchers were interested in the following complications: 90-day risks of postoperative surgical site infection, sepsis, periprosthetic joint infection, pulmonary embolism, deep venous thrombosis, wound dehiscence, seroma, stroke, pneumonia, respiratory failure, myocardial infarction, acute kidney injury, urinary tract infection, readmission, and mortality.

Using data from 2004 to 2020 to assess trends in insurance coverage, the team found that during this time period, the proportion of patients with Medicare Advantage increased from 7.9% to 34.4%, while those with traditional Medicare decreased from 83.7% to 54.0%.

Of the 697,317 patients who underwent primary elective TJA from 2015 to 2020, 471,439 (67.6%) had traditional Medicare coverage and 225,878 (32.4%) had Medicare Advantage coverage. After controlling for confounders, patients with Medicare Advantage had higher odds of surgical site infection, periprosthetic joint infection, stroke, and acute kidney injury, but lower odds of urinary tract infection.

“The sheer number of patients over the age of 65 that were enrolled in Medicare Advantage plans in 2020 was the most important result,” said Dr. Heckmann to OTW. “Also, the fact that Medicare Advantage patients had slightly higher rates of complications is another important finding that warrants further investigation.”

Racial Differences in Enrollment

The researchers found that a higher proportion of Black patients (8.29% compared with 4.62%) and a lower proportion of White patients (84.0% compared with 89.2%) were enrolled in Medicare Advantage compared with traditional Medicare.

“The fact that Black patients enrolled in Medicare Advantage plans at nearly twice the rate as White patients is a finding that surprised us and warrants further investigation,” explained Dr. Heckmann to OTW. “We need to understand the drivers and causes of these trends and better understand if the differences in outcomes worsen or improve over time.”