Study Finds Disparities in Patients Having Knee Replacement in ASCs

Sarasota, FL (WorkersCompensation.com) – In 2018, the Centers for Medicare & Medicaid Services (CMS) removed Total Knee Arthroplasty (TKA) procedures, also known as total knee replacement, from the Inpatient Only List, allowing the procedures to be performed in an inpatient or outpatient setting. The change in requirement was a move intended to lower costs while retaining patient safety as outpatient procedures cost less than inpatient procedures.

According to recent statistics from the American Academy of Orthopaedic Surgeons, 2.8 million hip and knee replacements were performed last year, representing a 14 percent increase from the previous year. Additionally, 22,427 cases were performed in outpatient Ambulatory Surgery Centers (ASCs), which represents an increase of 57 percent from the previous year.

While studies showed that these surgeries could be reasonably performed in an outpatient setting, the association of CMS’s removal from the Inpatient Only List and actual utilization and outcomes have not been well studied. Researchers from the University of Rochester Medical Center in Rochester, New York, reviewed patient data from 2016 to 2019 to determine patient factors associated with outpatient TKR procedures. The researchers reviewed whether surgeries were performed inpatient or outpatient, and reviewed secondary outcomes including 30 and 90 day readmissions, postoperative emergency department visits, non–home discharge, and total cost of the surgical encounter. Encounter review total was 61,651, which represented 55,067 patients overall.

A total of 37,588 TKR procedures were performed, with 18,819 performed after the procedure was removed from the Inpatient Only List. The researchers saw an increase in the utilization of ASCs starting at 6.7 percent in 2018, 11.2 percent in 2019.

The unadjusted 30-day and 90-day readmission rate for surgeries done after 2018 was .7 percent and 1.1 percent. For 30 and 90-day emergency department visits, the rates were 1.2 percent, and 1.7 percent. The number of patients discharged to a facility totaled 29.2 percent, and the average cost was $15,398 per encounter, which represented a slight increase in cost.

The researchers noted that their findings were consistent with other studies showing that the rate of outpatient TKR procedures among Medicare patients increased 0.2 percent in 2017 to 36.4 percent in the second quarter of 2019. However, the researchers noted that that there were fewer non-Hispanic Black patients, fewer female patients, and fewer Medicare and Medicaid dual eligible patients for the ASC procedures. The researchers feel that the findings raise questions of whether these patients may have reduced access to outpatient facilities for replacement surgeries, and whether there may be a potential disincentive to care for patients of these demographics.

The researchers posed the question of whether physicians may be carrying out inadequate risk assessments, or whether the surgeons themselves perform joint replacements less commonly in an ASC, or perhaps the issue may be facility choice in that the facility was not equipped for outpatient procedures.

Overall, the researchers believe that the findings raise questions of whether the decision to pull TKR off the Inpatient Only List could have worsened racial, ethnic, gender gaps in access to care. The researchers believe that ongoing studies are necessary to monitor unintended worsening of disparities as a result of CMS policy change.

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