Increase in surgeons performing outpatient anterior cervical spine surgery leads to a shift in case volumes over time

Database analysis comparing incidence and complication rates between inpatient and outpatient laminotomies for lumbar disc herniation

Background

Lumbar disc herniation (LDH) is a common condition that can be characterized with disabling pain. While most patients recover without surgery, some still require operative intervention. The epidemiology and trends of laminotomy for LDH have not been recently studied, and current practice patterns might be different from historical norms. This study aimed to investigate the trends of inpatient and outpatient laminotomies for LDH and compare complication rates between these two sites of service.

Methods

A large, national database was utilized to identify patients > 8 years old who underwent a laminotomy for LDH between 2009 and 2019. Two cohorts were created based on site of surgery: inpatient versus outpatient. The outpatient cohort was defined as patients who had a length of stay less than 1 day without any associated hospitalization. Epidemiologic analyses for these cohorts were performed by demographics. Patients in both groups were then 1:1 propensity-score matched based on age, sex, insurance type, geographic region, and comorbidities. Ninety-day postoperative complications were compared between cohorts utilizing multivariate logistic regressions.

Results

The average incidence of laminotomy for LDH was 13.0 per 10,000 persons-years. Although the national trend in incidence had not changed from 2009 to 2019, the proportion of outpatient laminotomies significantly increased in this time period (p=.02). Outpatient laminotomies were more common among younger and healthier patients. Patients with inpatient laminotomies had significantly higher rates of surgical site infections (odds ratio [OR] 1.61, p<.001), venous thromboembolism (VTE) (OR 1.96, p<.001), hematoma (OR 1.71, p<.001), urinary tract infections (OR 1.41, p<.001), and acute kidney injuries (OR 1.75, p=.001), even when controlling for selected confounders.

Conclusions

Our study demonstrated an increasing trend in the performance of laminotomy for LDH toward the outpatient setting. Even when controlling for certain confounders, patients requiring inpatient procedures had higher rates of postoperative complications. This study highlights the importance of carefully evaluating the advantages and disadvantages of performing these procedures in an outpatient versus inpatient setting.

Growing utilization of ambulatory spine surgery in Medicare patients from 2010-2021

Background

There is growing interest in transitioning various surgical procedures to the outpatient care setting. However, for Medicare patients, the site of service for surgical procedures is influenced by regulations within the Inpatient and Outpatient Prospective Payment Systems. The purpose of this study is to quantify changes in utilization of outpatient spine surgery within the Medicare population, as well as to determine changes in outpatient volume after removal of a procedure from the "inpatient-only" list.

Methods

This is a cross-sectional study of Medicare billing database information for selected spine procedures included in the Medicare Physician/Supplier Procedure Summary (PSPS) public use files from 2010-2021. These files include aggregated data from Medicare Part B fee-for-service claims, published yearly. Procedures from Healthcare Common Procedural Coding System (HCPCS) code ranges 22010-22899 and 62380-63103 were selected for analysis, limited to surgical services delivered in the inpatient, hospital outpatient department (HOPD), and ambulatory surgical center (ASC) settings. For each HCPCS code included, estimates of the total number of services and corresponding changes in volume were calculated.

Results

Within the range of codes included in the study, the total number of outpatient spine procedures rose approximately 193% from 2010 to 2021, with compound annual growth rate (CAGR) for outpatient procedures per year of 9.9% for HOPDs and 15.7% for ASCs (-2.2% for inpatient procedures). Within this period, the ASC list grew from 12 procedures to 58 procedures. In 2021, the highest volume ASC procedure was HCPCS 63047, at approximately 4970 procedures.

Conclusions

This study demonstrates a trend of increasing utilization of HOPDs and ASCs for spine procedures among Medicare beneficiaries from 2010 to 2021. Though HOPDs are currently more widely utilized, the ongoing additions of spine procedures to the ASC covered procedures list may shift this balance.