P63. Outpatient vs inpatient single-level cervical disc arthroplasty: An all-payer database analysis of 90-day complications and costs

BACKGROUND CONTEXT Despite a trend toward outpatient spine surgery, safety evidence for ambulatory cervical disc arthroplasty (CDA) is limited. PURPOSE To analyze differences in 90-day complications and costs between outpatient and inpatient cervical disc arthroplasties (CDAs). STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE This was a retrospective review of all-payer claims from the MarinerSpine dataset accessed through the PearlDiver research program. Current Procedural Terminology code 22856 was used to identify patients undergoing standalone single-level CDAs. Patients undergoing concurrent anterior/posterior fixation, hybrid surgery (fusion + replacement) and/or revision surgery were excluded from the study. Service Location codes were used to identify patients undergoing surgery as an inpatient or an outpatient. A 1:1 propensity score matching using age, gender, plan and comorbidity burden as co-variates was used to create similar groups of inpatient and outpatient CDAs. OUTCOME MEASURES Ninety-day medical and surgical complications. METHODS Multivariate logistic regression analyses assessed differences in 90-day complications, readmissions and revisions between inpatient and outpatient CDAs. Generalized linear regression modeling was used to identify differences in 90-day reimbursement between inpatient and outpatient CDAs. RESULTS After matching, a total of 1,149 CDAs were included in the study. Of them, 499 (43.4%) were outpatient CDAs. Multivariate analyses showed no significant differences between outpatient and inpatient CDAs with regards to wound complications (p=0.992), urinary tract infections (p=0.332), pneumonia (p=0.398), acute myocardial infarction (p=0.999), acute renal failure (p=0.491), stroke (p=0.999), all-cause medical complications (p=0.305), readmissions (p=0.363) and revision surgeries (p=0.425) within 90-days of the index procedure. CDAs performed in outpatient settings were associated with significant risk-adjusted cost savings of nearly $8,000 across the entire 90-day period. CONCLUSIONS Outpatient CDA appears to be safe and cost-efficacious in a carefully selected patient cohort. These findings provide support for transitioning CDAs to an outpatient setting. Future studies are warranted to assess whether there are any differences in patient-reported outcomes between outpatient and inpatient CDAs. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.