The Removal of Total Hip Arthroplasty From the Inpatient-Only List has Improved Patient Selection and Expanded Optimization Efforts.

BACKGROUND

On January 1, 2020, the Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the Inpatient-Only (IPO) list. This study evaluated patient demographics and comorbidities, preoperative optimization efforts, and 30-day outcomes of patients undergoing outpatient THA before and after IPO removal. The authors hypothesized that patients undergoing THA post-IPO removal would have improved optimization of modifiable risk factors and equivalent 30-day outcomes.

METHODS

There were 17,063 outpatient THAs in a national database stratified by surgery performed before (2015 to 2019: 5,239 patients) and after IPO (2020: 11,824 patients) removal. Demographics, comorbidities, and 30-day outcomes were compared with univariable and multivariable analyses. Preoperative optimization thresholds were established for the following modifiable risk factors: albumin, creatinine, hematocrit, smoking history, and body mass index. The percentage of patients who fell outside the thresholds in each cohort were compared.

RESULTS

Patients undergoing outpatient THA post-IPO removal were significantly older; mean age 65 years (range, 18 to 92) versus 62 (range, 18 to 90) years (P < .01), with a higher percentage of American Society of Anesthesiologists scores 3 and 4 (P < .01). There was no difference in 30-day readmissions (P = .57) or reoperations (P = 1.00). A significantly lower percentage of patients fell outside the established threshold for albumin (P < .01) post-IPO removal, and trended towards lower percentages for hematocrit and smoking status.

CONCLUSION

The removal of THA from the IPO list expanded patient selection for outpatient arthroplasty. Preoperative optimization is critical to minimize postoperative complications, and the current study demonstrates that 30-day outcomes have not worsened post-IPO removal.