Primary single-level lumbar microdisectomy/decompression at a free-standing ambulatory surgical center vs a hospital-owned outpatient department—an analysis of 90-day outcomes and costs

ABSTRACT BACKGROUND CONTEXT While free-standing ambulatory surgical centers (ASCs) have been extolled as lower cost settings than hospital outpatient facilities/departments (HOPDs) for performing routine elective spine surgeries, differences in 90-day costs and complications have yet to be compared between the two types of treatment facilities. PURPOSE We carried a comprehensive analysis to report the differences on payments to providers and facilities as a reflection of true costs to patients, employers and health plans for patients undergoing primary, single-level lumbar microdiscectomy/decompression at ASC versus HOPD. STUDY DESIGN Retrospective review of Medicare advantage and commercially insured enrollees from the Humana dataset from 2007 to 2017Q1. OUTCOME MEASURES To understand the differences in 90-day complications, readmissions, emergency department visits and costs for patients undergoing primary, single-level lumbar microdiscectomy/decompressions at an ASC versus HOPD. METHODS The Humana 2007 to 2017Q1 was queried using Current Procedural Terminology codes to identify patients undergoing primary, single-level lumbar microdiscectomy/decompressions. Patients undergoing two-level surgery, open laminectomies, fusions, revision discectomies, and/or deformities were excluded. Service Location codes for HOPD (Location Code 22) and free-standing ASC (Location Code 24) were used to determine surgery treatment facilities. Using propensity scoring, we matched two groups who had surgery performed in ASCs or HOPDs based on age, gender, race, region and Elixhauser comorbidity index. Multivariable logistic regression analyses were performed on matched cohorts to assess for differences in 90-day outcomes between facilities, while controlling for age, gender, race, region, plan, and Elixhauser comorbidity index. RESULTS A total of 1,077 and 10,475 primary single-level decompressions were performed in ASCs and HOPDs, respectively. Following a matching algorithm with propensity scoring, the two cohorts were comprised of 990 patients each. Observed differences in 90-day complication rates were not statistically or clinically significant (ASC=9.1% vs. HOPD=10.3%; p=.362) nor were readmissions (ASC=4.5% vs. HOPD=5.3%; p=.466). On average, performing surgery in an ASC versus HOPD resulted in significant cost savings of over $2,000/case in Medicare Advantage ($5,814 vs. $7,829) and over $3,500/case ($10,116 vs. $13,623) in commercial beneficiaries. CONCLUSION Performing single-level decompression surgeries in an ASC compared with HOPDs was associated with approximately $2,000 to $3,500 cost-savings per case with no statistically significant impact on complication or readmission rates.