Predicting Inpatient Status After Total Hip Arthroplasty in Medicare-Aged Patients

Area of Science:

• Orthopedic Surgery
• Health Services Research
• Geriatric Medicine

Background:

• Centers for Medicare and Medicaid Services is considering removing total hip arthroplasty (THA) from its inpatient-only list.
• This policy change necessitates identifying suitable inpatient candidates for THA among Medicare beneficiaries.
• Developing a reliable risk stratification tool is essential for this patient population.

Purpose of the Study:

• To develop and internally validate a risk stratification nomogram for identifying optimal inpatient candidates for total hip arthroplasty (THA).
• To aid decision-making for Medicare-aged patients undergoing THA as outpatient procedures become more feasible.

Main Methods:

• Utilized the American College of Surgeons National Surgical Quality Improvement Program database (2006-2015).
• Identified patients aged over 65 undergoing primary THA.
• Assessed demographic, comorbid, and perioperative variables using multivariable logistic regression to construct a predictive nomogram for inpatient stay (>2 days).

Main Results:

• Analyzed 30,587 inpatient and 17,024 outpatient THAs.
• Key predictors of inpatient status included heart failure, simultaneous bilateral THA, age >80, female gender, and dependent functional status.
• The prediction algorithm demonstrated good accuracy (bias-corrected concordance index of 0.69) and excellent calibration.

Conclusions:

• The developed model accurately and simply identifies optimal inpatient candidates for THA in Medicare-aged patients.
• This risk stratification tool provides a framework for guiding discussions and decisions regarding inpatient vs. outpatient THA.
• Facilitates adaptation to potential policy changes by the Centers for Medicare and Medicaid Services regarding inpatient-only procedures.