Can Total Knee Arthroplasty Be Performed Safely as an Outpatient in the Medicare Population?
BACKGROUND
The Centers for Medicare and Medicaid Services has solicited public comments for the 2017 Proposed Rule to consider removing total knee arthroplasty (TKA) from the Inpatient Only List. The purpose of this study is to compare the complication rates between outpatient (same-day discharge), short-stay (discharge within 1 day), and inpatient TKA and to identify the ideal candidates for a short-stay or outpatient procedure.


METHODS
We queried the American College of Surgeons-National Surgical Quality Improvement Program database for patients over age 65 years who underwent TKA from 2014 to 2015. Demographics, comorbidities, 30-day complications, and readmission rates were compared between patients after outpatient, short-stay, and inpatient procedures. A multivariate regression analysis was then performed to identify at-risk patients who should not be candidates for outpatient or short-stay TKA.


RESULTS
Of the 49,136 Medicare-aged TKA patients, 365 (0.7%) were outpatient, 3033 (6%) were short-stay and 45,738 (93%) were inpatient. Short-stay patients had a lower complication rate than both the outpatient and inpatient groups (2% vs. 8% vs. 8%, P < .001). Independent risk factors (all P < .05) for experiencing a complication or requiring an inpatient stay include female gender (odds ratio [OR] 1.655), general anesthesia (OR 1.282), diabetes mellitus (OR 1.171), chronic obstructive pulmonary disease (OR 1.579, P < .001), hypertension (OR 1.144), kidney disease (OR 1.425), American Society of Anesthesiologists Score 4 (OR 1.748), body mass index >35 kg/m2 (OR 1.265), and age >75 years (OR 1.429).


CONCLUSION
TKA can be performed safely as an outpatient in a subset of healthy Medicare patients with a complication rate similar to an inpatient stay. A 23-hour stay, however, may be the "sweet spot" that minimizes complications in this population.
['Courtney|P Maxwell|PM|', 'Froimson|Mark I|MI|', 'Meneghini|R Michael|RM|', 'Lee|Gwo-Chin|GC|', 'Della Valle|Craig J|CJ|']
D000368:Aged D000369:Aged, 80 and over D019645:Arthroplasty, Replacement, Knee D015897:Comorbidity D005260:Female D006801:Humans D007297:Inpatients D007902:Length of Stay D008297:Male D006278:Medicare D015999:Multivariate Analysis D016017:Odds Ratio D010045:Outpatients D010351:Patient Discharge D010359:Patient Readmission D061214:Patient Safety D011183:Postoperative Complications D058996:Quality Improvement D011787:Quality of Health Care D012044:Regression Analysis D012189:Retrospective Studies D012307:Risk Factors D014481:United States
total knee arthroplasty outpatient Inpatient Only List complications health policy