Developing Mixed-Effects Models to Compare the Predictive Ability of Various Comorbidity Indices in a Contemporary Cohort of Patients Undergoing Lumbar Fusion
BACKGROUND AND OBJECTIVE: As incidence of operative spinal pathology continues to grow, so do the rates of lumbar spinal fusion procedures. Comorbidity indices can be used preoperatively to predict potential complications. However, there is a paucity of research defining the optimal comorbidity indices in patients undergoing spinal fusion surgery. We aimed to use modeling strategies to evaluate the predictive validity of various comorbidity indices and combinations thereof. METHODS: Patients who underwent spinal fusion were queried using data from the Nationwide Readmissions Database for the years 2016 through 2019. Using comorbidity indices as predictor variables, receiver operating characteristic curves were developed for pertinent complications such as mortality, nonroutine discharge, top-quartile cost, top-quartile length of stay, and 30-day readmission. RESULTS: A total of 750 183 patients were included. Nonroutine discharges occurred in 161 077 (21.5%) patients. The adjusted all-payer cost for the procedure was $37 616.97 ± $27 408.86 (top quartile: $45 409.20), and the length of stay was 4.1 ± 4.4 days (top quartile: 8.1 days). By comparing receiver operating characteristics of various models, it was found that models using Frailty + Elixhauser Comorbidity Index (ECI) as the primary predictor performed better than other models with statistically significant P -values on post hoc testing. However, for prediction of mortality, the model using Frailty + ECI was not better than the model using ECI alone ( P = .23), and for prediction of all-payer cost, the ECI model outperformed the models using frailty alone ( P < .0001) and the model using Frailty + ECI ( P < .0001). CONCLUSION: This investigation is the first to use big data and modeling strategies to delineate the relative predictive utility of the ECI and Johns Hopkins Adjusted Clinical Groups comorbidity indices for the prognostication of patients undergoing lumbar fusion surgery. With the knowledge gained from our models, spine surgeons, payers, and hospitals may be able to identify vulnerable patients more effectively within their practice who may require a higher degree of resource utilization.
Surgical Intervention for Primary B-cell Lymphoma of the Spine
Clinical Spine Surgery | September 9, 2023 | Volume: 37 | Issue: 7 | Pages: 296-304
Study Design: Systematic review and meta-analysis. Objective: To perform a systematic review of the clinical symptoms, radiographic findings, and outcomes after spinal decompression in B-cell lymphoma. Summary of Background Data: B-cell lymphoma is a potential cause of spinal cord compression that presents ambiguously with nonspecific symptoms and variable imaging findings. Surgical decompression is a mainstay for both diagnosis and management, especially in patients with acute neurological deficits; however, the efficacy of surgical intervention compared with nonoperative management is still unclear. Methods: The databases of Medline, PubMed, and the Cochrane Database of Systemic Reviews were queried for all articles reporting spinal B-cell lymphoma. Data on presenting symptoms, treatments, survival outcomes, and histologic markers were extracted. Using the R software “survival” package, we generated bivariate and multivariate Cox survival regression models and Kaplan-Meier curves. Results: In total, 65 studies were included with 72 patients diagnosed with spinal B-cell lymphoma. The mean age was 56.22 (interquartile range: 45.00–70.25) with 68% of patients being males and 4.2% of patients being immunocompromised. Back pain was the most common symptom (74%), whereas B symptoms and cauda equina symptoms were present in 6% and 29%, respectively. The average duration of symptoms before presentation was 3.81 months (interquartile range: 0.45–3.25). The most common location was the thoracic spine (53%), with most lesions being hyperintense (28%) on T2 magnetic resonance imaging. Surgical resection was performed in 83% of patients. Symptoms improved in 91% of patients after surgery and in 80% of patients treated nonoperatively. For all 72 patients, the overall survival at 1 and 5 years was 85% (95% CI: 0.749–0.953; n = 72) and 66% (95% CI: 0.512–0.847; n = 72), respectively. Conclusion: Although surgery is usually offered in patients with acute spinal cord compression from B-cell lymphoma, chemotherapy and radiation alone offer a hopeful alternative to achieve symptomatic relief, particularly in patients who are unable to undergo surgery.
Editorial. Four-level anterior cervical discectomy and fusion: a cautionary tale
OBJECTIVE The Quality Outcomes Database (QOD) was established in 2012 by the NeuroPoint Alliance, a nonprofit organization supported by the American Association of Neurological Surgeons. Currently, the QOD has launched six different modules to cover a broad spectrum of neurosurgical practice—namely lumbar spine surgery, cervical spine surgery, brain tumor, stereotactic radiosurgery (SRS), functional neurosurgery for Parkinson’s disease, and cerebrovascular surgery. This investigation aims to summarize research efforts and evidence yielded through QOD research endeavors. METHODS The authors identified all publications from January 1, 2012, to February 18, 2023, that were produced by using data collected prospectively in a QOD module without a prespecified research purpose in the context of quality surveillance and improvement. Citations were compiled and presented along with comprehensive documentation of the main study objective and take-home message. RESULTS A total of 94 studies have been produced through QOD efforts during the past decade. QOD-derived literature has been predominantly dedicated to spinal surgical outcomes, with 59 and 22 studies focusing on lumbar and cervical spine surgery, respectively, and 6 studies focusing on both. More specifically, the QOD Study Group—a research collaborative between 16 high-enrolling sites—has yielded 24 studies on lumbar grade 1 spondylolisthesis and 13 studies on cervical spondylotic myelopathy, using two focused data sets with high data accuracy and long-term follow-up. The more recent neuro-oncological QOD efforts, i.e., the Tumor QOD and the SRS Quality Registry, have contributed 5 studies, providing insights into the real-world neuro-oncological practice and the role of patient-reported outcomes. CONCLUSIONS Prospective quality registries are an important resource for observational research, yielding clinical evidence to guide decision-making across neurosurgical subspecialties. Future directions of the QOD efforts include the development of research efforts within the neuro-oncological registries and the American Spine Registry—which has now replaced the inactive spinal modules of the QOD—and the focused research on high-grade lumbar spondylolisthesis and cervical radiculopathy.
How closely are outcome questionnaires correlated to patient satisfaction after cervical spine surgery for myelopathy?
Journal of Neurosurgery: Spine | March 10, 2023 | Volume: 38 | Issue: 5 | Pages: 521-529
OBJECTIVE Patient-reported outcomes (PROs) have become the standard means to measure surgical outcomes. Insurers and policy makers are also increasingly utilizing PROs to assess the value of care and measure different aspects of a patient’s condition. For cervical myelopathy, it is currently unclear which outcome measure best reflects patient satisfaction. In this investigation, the authors evaluated patients treated for cervical myelopathy to determine which outcome questionnaires best correlate with patient satisfaction. METHODS The Quality Outcomes Database (QOD), a prospectively collected multi-institutional database, was used to retrospectively analyze patients undergoing surgery for cervical myelopathy. The North American Spine Society (NASS) satisfaction index, Neck Disability Index (NDI), numeric rating scales for neck pain (NP-NRS) and arm pain (AP-NRS), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scale were evaluated. RESULTS The analysis included 1141 patients diagnosed with myelopathy, of whom 1099 had an NASS satisfaction index recorded at any of the follow-up time points. Concomitant radiculopathy was an indication for surgery in 368 (33.5%) patients, and severe neck pain (NP-NRS ≥ 7) was present in 471 (42.8%) patients. At the 3-month follow-up, NASS patient satisfaction index scores were positively correlated with scores for the NP-NRS (r = 0.30), AP-NRS (r = 0.32), and NDI (r = 0.36) and negatively correlated with EQ-5D (r = −0.38) and mJOA (r = −0.29) scores (all p < 0.001). At the 12-month follow-up, scores for the NASS index were positively correlated with scores for the NP-NRS (r = 0.44), AP-NRS (r = 0.38), and NDI (r = 0.46) and negatively correlated with scores for the EQ-5D (r = −0.40) and mJOA (r = −0.36) (all p < 0.001). At the 24-month follow-up, NASS index scores were positively correlated with NP-NRS (r = 0.49), AP-NRS (r = 0.36), and NDI (r = 0.49) scores and negatively correlated with EQ-5D (r = −0.44) and mJOA (r = −0.38) scores (all p < 0.001). CONCLUSIONS Neck pain was highly prevalent in patients with myelopathy. Notably, improvement in neck pain–associated disability rather than improvement in myelopathy was the most prominent PRO factor for patients. This finding may reflect greater patient concern for active pain symptoms than for neurological symptoms caused by myelopathy. As commercial payers begin to examine novel remuneration strategies for surgical interventions, thoughtful analysis of PRO measurements will have increasing relevance.
Predictive model for long-term patient satisfaction after surgery for grade I degenerative lumbar spondylolisthesis: insights from the Quality Outcomes Database
OBJECTIVE Since the enactment of the Affordable Care Act in 2010, providers and hospitals have increasingly prioritized patient-centered outcomes such as patient satisfaction in an effort to adapt the “value”-based healthcare model. In the current study, the authors queried a prospectively maintained multiinstitutional spine registry to construct a predictive model for long-term patient satisfaction among patients undergoing surgery for Meyerding grade I lumbar spondylolisthesis. METHODS The authors queried the Quality Outcomes Database for patients undergoing surgery for grade I lumbar spondylolisthesis between July 1, 2014, and June 30, 2016. The primary outcome of interest for the current study was patient satisfaction as measured by the North American Spine Surgery patient satisfaction index, which is measured on a scale of 1–4, with 1 indicating most satisfied and 4 indicating least satisfied. In order to identify predictors of higher satisfaction, the authors fitted a multivariable proportional odds logistic regression model for ≥ 2 years of patient satisfaction after adjusting for an array of clinical and patient-specific factors. The absolute importance of each covariate in the model was computed using an importance metric defined as Wald chi-square penalized by the predictor degrees of freedom. RESULTS A total of 502 patients, out of a cohort of 608 patients (82.5%) with grade I lumbar spondylolisthesis, undergoing either 1- or 2-level decompression (22.5%, n = 113) or 1-level decompression and fusion (77.5%, n = 389), met the inclusion criteria; of these, 82.1% (n = 412) were satisfied after 2 years. On univariate analysis, satisfied patients were more likely to be employed and working (41.7%, n = 172, vs 24.4%, n = 22; overall p = 0.001), more likely to present with predominant leg pain (23.1%, n = 95, vs 11.1%, n = 10; overall p = 0.02) but more likely to present with lower Numeric Rating Scale score for leg pain (median and IQR score: 7 [5–9] vs 8 [6–9]; p = 0.05). Multivariable proportional odds logistic regression revealed that older age (OR 1.57, 95% CI 1.09–2.76; p = 0.009), preoperative active employment (OR 2.06, 95% CI 1.27–3.67; p = 0.015), and fusion surgery (OR 2.3, 95% CI 1.30–4.06; p = 0.002) were the most important predictors of achieving satisfaction with surgical outcome. CONCLUSIONS Current findings from a large multiinstitutional study indicate that most patients undergoing surgery for grade I lumbar spondylolisthesis achieved long-term satisfaction. Moreover, the authors found that older age, preoperative active employment, and fusion surgery are associated with higher odds of achieving satisfaction.