Estimating Intraoperative Neurophysiological Monitoring Rates for Anterior Cervical Discectomy and Fusion: Are Diagnostic or Procedural Codes Accurate?

Abstract

Background: The utility of intraoperative neurophysiological monitoring (IONM) is well established for some spine surgeries (eg, intramedullary tumor resection, scoliosis deformity correction), but its benefit for most degenerative spine surgery, including anterior cervical discectomy and fusion (ACDF), remains debated. National datasets provide "big data" approaches to study the impact of IONM on spine surgery outcomes; however, if administrative coding in these datasets misrepresents actual IONM usage, conclusions will be unreliable. The objective of this study was to compare estimated rates (administrative coding) to actual rates (chart review) of IONM for ACDF at our institution and extrapolate findings to estimated rates from 2 national datasets.Methods: Patients were included from 3 administrative coding databases: the authors' single institution database, the Nationwide Inpatient Sample (NIS), and the National Surgical Quality Improvement Program (NSQIP). Estimated and actual institutional rates of IONM during ACDF were determined by administrative codes (International Classification of Diseases [ICD] or Current Procedural Terminology [CPT]) and chart review, respectively. National rates of IONM during ACDF were estimated using the NIS and NSQIP datasets.Results: Estimated institutional rates of IONM for ACDF were much higher with CPT than ICD coding (73.2% vs 16.5% in 2019). CPT coding for IONM better approximated actual IONM usage at our institution (74.6% in 2019). Estimated IONM utilization rates for ACDF in national datasets varied widely: 0.76% in CPT-based NSQIP and 18.4% in ICD-based NIS.Conclusions: ICD coding underestimated IONM usage during ACDF at our institution, whereas CPT coding was more accurate. Unfortunately, the CPT-based NSQIP is nearly devoid of IONM codes, as it has not been a collection focus of that surgical registry. ICD-based datasets, such as the NIS, likely fail to accurately capture IONM usage. Multicenter and/or national datasets with accurate IONM utilization data are needed to inform surgeons, insurers, and guideline authors on whether IONM has benefit for various spine surgery types.Level of Evidence: 4. Clinical Relevance: Currently available national databases based on administrative codes do not accurately reflect IONM usage.

The Utilization of Intraoperative Neurophysiological Monitoring for Lumbar Decompression and Fusion Surgery in New York State

“…In our study, neurological deficits were found in only 0.6% (210 out of 34,592 patients). One study investigated the IONM coding accuracy in cervical spine surgery with the NIS database and reported that ICD coding underestimated IONM usage, whereas Current Procedural Terminology (CPT) coding was more accurate 33 . That study concluded that currently, available national databases based on administrative codes do not accurately reflect IONM usage 33 .…”

“…One study investigated the IONM coding accuracy in cervical spine surgery with the NIS database and reported that ICD coding underestimated IONM usage, whereas Current Procedural Terminology (CPT) coding was more accurate. 33 That study concluded that currently, available national databases based on administrative codes do not accurately reflect IONM usage. 33 Since our study used ICD codes for IONM, the neurological deficit rate may In our study results, neither neurological deficits nor LOS showed a difference between the IONM and non-IONM groups.…”

“…33 That study concluded that currently, available national databases based on administrative codes do not accurately reflect IONM usage. 33 Since our study used ICD codes for IONM, the neurological deficit rate may In our study results, neither neurological deficits nor LOS showed a difference between the IONM and non-IONM groups. Paradoxically, our results showed that nerve root injury was significantly higher in the IONM group, and spinal cord injury was higher in the non-IONM group.…”

Utilization Trends of Intraoperative Neuromonitoring for Anterior Cervical Discectomy and Fusion in New York State

“…In the NIS and NSQIP databases, IONM utilization varied widely from 0.76% to 18.4%, respectively. 28 The implication is that national databases and SPARCS may be unequipped to fully understand the utilization of IONM. It is unclear if IONM alerts significantly affect real-time clinical decision-making during ACDF surgery to prevent neurological injury and postoperative deficit.…”

Developing an Automated Registry (Autoregistry) of Spine Surgery Using Natural Language Processing and Health System Scale Databases

“…5 Moreover, while billing data containing codes from the International Classification of Diseases and Current Procedural Terminology might also seem to provide readily available structured data sets, these similarly often lack specific clinical parameters of interest or fail to adequately identify performed procedures. 6-8…”