Comparative Analysis of Learning Curve, Complexity, Psychological Stress, and Work Relative Value Units for CPT 62380 Endoscopic Lumbar Spinal Decompression vs Traditional Lumbar Spine Surgeries: A Paired Rasch Survey Study

Two examples of outlier-sensitive means statistics (outfit analysis) based on the conventional sum of squared standardized residuals, which is more sensitive to unexpected observations, are shown. Surgeon responses on the difficulty of Current Procedural Terminology (CPT) code 22102 compared with the lumbar endoscopy procedure showed a greater outfit from the model predicted by the Rasch analysis (indicated by the red vertical line) than for CPT code 22869 (green vertical line), thereby suggesting the presence of confounding factors affecting responses on item for CPT code 22102. Infit (not shown in this graph) and outfit data between 0.6 and 1.4 indicate a good fit of the Rasch model. Outside these parameters, confounding factors are likely.

Five hundred forty-two spine surgeons accessed the online survey aimed to obtain objective measures of the learning curve effort to obtain adequate skill level to perform the endoscopic lumbar decompression operation, its psychological intensity and stress on the surgeon, and its associated work effort in comparison to other commonly performed lumbar spinal surgeries based on the input of spine surgeons who perform these procedures. Three hundred twenty-two surgeons started the survey, and 150 submitted a valid survey recording, yielding a completion rate of 43.1%.

The majority of responding spine surgeons were neurosurgeons (43.3%). Orthopedic surgeons comprised 38.6% of the respondents, followed by 15% of surgeons who dedicated their practice entirely to the spine. Only 2.4% of the response came from pain management physicians. Therefore, 96.9% of respondents had a postgraduate education in a surgical specialty. Of the 150 responding surgeons, 84.3% worked in an urban practice setting, 8.7% worked in a suburban environment, followed by 7.1% who worked in a rural area.

Most surgeons were members of professional surgeons organizations including the North American Spine Society (NASS; 26.8%), The Brazilian Spine Society – Sociedade Brasiliera de Columna (SBC; 22%), Inter-American Society for Minimally Invasive Spine Surgery – Sociedad Interamericana de Cirurgia de Columna Minimamente Invasiva (SICCMI; 14.2$), American Association of Neurological Surgeons (AANS; 12.6%), American Academy of Orthopedic Surgeons (AAOS; 12.6%), Society For Minimally Invasive Spine Surgery (SMISS; 12.6%), Congress of Neurological Surgeons (CNS; 11.8%), Sociedad Iberolatinoamericana de Columna (SILACO; 11.0%), Korean Minimally Invasive Spine Society (KOMISS; 8.7%), International Society For The Advancement of Spine Surgery (ISASS; 7.9%), European Spine Society (7.1%), Korean Endoscopic Spine Society (KOSESS; 5.5%), KOMISS (8.7%) American Medical Association (AMA; 3.9%), International Society for Minimal Intervention in Spinal Surgery (ISMISS; 3.9%), Chinese Orthopedic Association (COA; 3.1%), Taiwanese Society of Endoscopy Spine Surgery (TSESS; 3.1%), AO Spine (3.9%), the Arab Spine Society (0.8%), and others, such as Asean MIST, the Mexican Spine Society – Associacion Mexicana de Cirujanos de Columna (AMCICO; 3.1%), Thai Minimally Invasive Spine Society (ThaiMISST; 1.6%), Federation of Latin American Neurosurgery Societies (FLANC 1.6%), Swiss Spine and Swiss Neurosurgical Society (0.6%), Deutsche Wirbelsaulengesellschaft (DWG; 0.6%), and Saudi Association of Neurosurgery (0.8%).

The item response theory (IRT) dichotomous Rasch analysis was employed to assess the learning curve difficulty of endoscopic lumbar decompression surgery compared with other commonly performed spinal surgeries (Table 1). Shown is the resulting Wright plot. On the left, the responding surgeons’ latent traits are written in logits (log odds) as estimates of true intervals of item difficulty and surgeon ability. The surgeons represented by horizontal bars at the top indicated that endoscopic spinal surgery is more complex to learn (positive logits) than those on the bottom (negative logits). On the right, the more challenging comparator surgeries are listed at the top vs the less challenging ones on the bottom. Directly across from 0, those surgeons had a 50% chance of considering the learning curve with endoscopic spine surgery as harder than those described by the comparator CPT code. One logit above suggests an approximately 75% chance that these comparator surgeries were considered more challenging than lumbar endoscopic surgery vs one logit below, which suggests an approximately 25% chance that the comparator surgeries were considered more straightforward than lumbar endoscopic surgery. There were assessment gaps above CPT code 63620 and below CPT code 63005. There were areas of redundancy with CPT codes 22102, 63005, 63047, 63030, 22532, and 22633, suggesting a similar degree of learning curve effort between these surgeries.

The item response theory (IRT) dichotomous Rasch analysis was employed to assess the mental effort and psychological stress of endoscopic lumbar decompression surgery compared with other commonly performed spinal surgeries (Table 1). Shown is the resulting Wright plot. On the left, the responding surgeons’ latent traits are written in logits (log odds) as estimates of true intervals of item difficulty and surgeon mental effort-related stress. The surgeons represented by horizontal bars at the top indicated that endoscopic spinal surgery is more stressful (positive logits) than those on the bottom (negative logits). On the right, the more stressful comparator surgeries are listed at the top vs the less stressful ones on the bottom. Directly across from 0, those surgeons had a 50% chance of considering the mental effort and psychological stress with endoscopic spine surgery as higher than those described by the comparator CPT code. One logit above suggests an approximately 75% chance that these comparator surgeries were considered more stressful than lumbar endoscopic surgery vs one logit below suggests an approximately 25% chance that the comparator surgeries were considered less stressful than lumbar endoscopic surgery. There were assessment gaps above CPT code 22533 and below CPT code 22869. There were areas of redundancy with CPT codes 22533, 22633, 22630, 22532, 22102, and 63030, suggesting a similar degree of stress between these surgeries.

The item response theory (IRT) dichotomous Rasch analysis was employed to assess the work effort difficulty of endoscopic lumbar decompression surgery compared with other commonly performed spinal surgeries (Table 1). Shown is the resulting Wright plot. On the left, the responding surgeons’ latent traits are written in logits (log odds) as estimates of true intervals of item difficulty and surgeon ability. The surgeons represented by horizontal bars at the top of the chart indicated that endoscopic spinal surgery requires more work effort (positive logits) than those on the bottom (negative logits). On the right, the more challenging comparator surgeries are listed at the top vs the less challenging ones on the bottom. Directly across from 0, those surgeons had a 50% chance of considering the work effort with endoscopic spine surgery as harder than those described by the comparator CPT code. One logit above suggests an approximately 75% chance that these comparator surgeries were considered more work than lumbar endoscopic surgery vs one logit below suggests an approximately 25% chance that the comparator surgeries were considered less work than lumbar endoscopic surgery. There were assessment gaps above CPT code 22532 and below CPT code 22869. There were areas of redundancy with CPT codes 22102, 63620, 22869, 63047, 22612, 22532, and 22533, suggesting a similar degree of difficulty between these surgeries.