Inpatient or Outpatient TKA? New Study Has Metrics

With the removal of total knee arthroplasty (TKA) from Medicare’s “inpatient only” list comes a few logistical challenges. Delving into these issues recently was the Department of Surgical and Perioperative Care at the Dell Medical School at the University of Texas at Austin.

Their work, “Enhanced Selection of Candidates for Same-Day and Outpatient Total Knee Arthroplasty,” appears in the October 9, 2019 edition of the Journal of Arthroplasty.

The research team examined 325 unilateral TKAs done on patients who completed the Perioperative Surgical Home preop optimization pathway. They then identified preoperatively determined factors associated with same day discharge and inpatient TKA (as defined by Medicare’s 2-midnight rule).

The team then performed a stepwise logistic regression model to identify preoperatively those factors which are associated with, first, same day discharge and then, second, with inpatient total knee arthroplasty. They then compared the models’ ability to correctly predict each patient’s length of stay category based only on each patient’s Risk Assessment and Prediction Tool (RAPT) score.

The research team discharged 32 of the TKA patients enrolled in the study on the same day and discharged 189 of the patients the next day while keeping 104 as inpatients. The researchers determined that lower body mass index (BMI) and fewer self-reported allergies were associated with same day discharge. The preoperatively determined factors associated with inpatient TKA were age, BMI, RAPT score, and surgery start time.

Co-author Kevin Bozic, M.D., M.B.A., chair of the Department of Surgery and Perioperative Care at that facility and study co-author explained the study findings to OTW, “We identified patient and procedural factors that can be determined preoperatively and are predictive of same day discharge or inpatient TKA. These findings can be helpful to patients and their surgical teams when planning for their surgical episode and have implications for hospitals as they make the transition from inpatient to outpatient TKA.”