Minimally invasive versus open transforaminal lumbar interbody fusion for grade I lumbar spondylolisthesis: 5-year follow-up from the prospective multicenter Quality Outcomes Database registry.

OBJECTIVE: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been used to treat degenerative lumbar spondylolisthesis and is associated with expedited recovery, reduced operative blood loss, and shorter hospitalizations compared to those with traditional open TLIF. However, the impact of MI-TLIF on long-term patient-reported outcomes (PROs) is less clear. Here, the authors compare the outcomes of MI-TLIF to those of traditional open TLIF for grade I degenerative lumbar spondylolisthesis at 60 months postoperatively. METHODS: The authors utilized the prospective Quality Outcomes Database registry and queried for patients with grade I degenerative lumbar spondylolisthesis who had undergone single-segment surgery via an MI or open TLIF method. PROs were compared 60 months postoperatively. The primary outcome was the Oswestry Disability Index (ODI). The secondary outcomes included the numeric rating scale (NRS) for back pain (NRS-BP), NRS for leg pain (NRS-LP), EQ-5D, North American Spine Society (NASS) satisfaction, and cumulative reoperation rate. Multivariable models were constructed to assess the impact of MI-TLIF on PROs, adjusting for variables reaching p < 0.20 on univariable analyses and respective baseline PRO values. RESULTS: The study included 297 patients, 72 (24.2%) of whom had undergone MI-TLIF and 225 (75.8%) of whom had undergone open TLIF. The 60-month follow-up rates were similar for the two cohorts (86.1% vs 75.6%, respectively; p = 0.06). Patients did not differ significantly at baseline for ODI, NRS-BP, NRS-LP, or EQ-5D (p > 0.05 for all). Perioperatively, MI-TLIF was associated with less blood loss (108.8 ± 85.6 vs 299.6 ± 242.2 ml, p < 0.001) and longer operations (228.2 ± 111.5 vs 189.6 ± 66.5 minutes, p < 0.001) but had similar lengths of hospitalizations (MI-TLIF 2.9 ± 1.8 vs open TLIF 3.3 ± 1.6 days, p = 0.08). Discharge disposition to home or home health was similar (MI-TLIF 93.1% vs open TLIF 91.1%, p = 0.60). Both cohorts improved significantly from baseline for the 60-month ODI, NRS-BP, NRS-LP, and EQ-5D (p < 0.001 for all comparisons). In adjusted analyses, MI-TLIF, compared to open TLIF, was associated with similar 60-month ODI, ODI change, odds of reaching ODI minimum clinically important difference, NRS-BP, NRS-BP change, NRS-LP, NRS-LP change, EQ-5D, EQ-5D change, and NASS satisfaction (adjusted p > 0.05 for all). The 60-month reoperation rates did not differ significantly (MI-TLIF 5.6% vs open TLIF 11.6%, p = 0.14). CONCLUSIONS: For symptomatic, single-level grade I degenerative lumbar spondylolisthesis, MI-TLIF was associated with decreased blood loss perioperatively, but there was no difference in 60-month outcomes for disability, back pain, leg pain, quality of life, or satisfaction between MI and open TLIF. There was no difference in cumulative reoperation rates between the two procedures. These results suggest that in appropriately selected patients, either procedure may be employed depending on patient and surgeon preferences.

Developing nonlinear k-nearest neighbors classification algorithms to identify patients at high risk of increased length of hospital stay following spine surgery.

OBJECTIVE: Spondylolisthesis is a common operative disease in the United States, but robust predictive models for patient outcomes remain limited. The development of models that accurately predict postoperative outcomes would be useful to help identify patients at risk of complicated postoperative courses and determine appropriate healthcare and resource utilization for patients. As such, the purpose of this study was to develop k-nearest neighbors (KNN) classification algorithms to identify patients at increased risk for extended hospital length of stay (LOS) following neurosurgical intervention for spondylolisthesis. METHODS: The Quality Outcomes Database (QOD) spondylolisthesis data set was queried for patients receiving either decompression alone or decompression plus fusion for degenerative spondylolisthesis. Preoperative and perioperative variables were queried, and Mann-Whitney U-tests were performed to identify which variables would be included in the machine learning models. Two KNN models were implemented (k = 25) with a standard training set of 60%, validation set of 20%, and testing set of 20%, one with arthrodesis status (model 1) and the other without (model 2). Feature scaling was implemented during the preprocessing stage to standardize the independent features. RESULTS: Of 608 enrolled patients, 544 met prespecified inclusion criteria. The mean age of all patients was 61.9 ± 12.1 years (± SD), and 309 (56.8%) patients were female. The model 1 KNN had an overall accuracy of 98.1%, sensitivity of 100%, specificity of 84.6%, positive predictive value (PPV) of 97.9%, and negative predictive value (NPV) of 100%. Additionally, a receiver operating characteristic (ROC) curve was plotted for model 1, showing an overall area under the curve (AUC) of 0.998. Model 2 had an overall accuracy of 99.1%, sensitivity of 100%, specificity of 92.3%, PPV of 99.0%, and NPV of 100%, with the same ROC AUC of 0.998. CONCLUSIONS: Overall, these findings demonstrate that nonlinear KNN machine learning models have incredibly high predictive value for LOS. Important predictor variables include diabetes, osteoporosis, socioeconomic quartile, duration of surgery, estimated blood loss during surgery, patient educational status, American Society of Anesthesiologists grade, BMI, insurance status, smoking status, sex, and age. These models may be considered for external validation by spine surgeons to aid in patient selection and management, resource utilization, and preoperative surgical planning.

Three-level ACDF versus 3-level laminectomy and fusion: are there differences in outcomes? An analysis of the Quality Outcomes Database cervical spondylotic myelopathy cohort.

OBJECTIVE: The authors sought to compare 3-level anterior with posterior fusion surgical procedures for the treatment of multilevel cervical spondylotic myelopathy (CSM). METHODS: The authors analyzed prospective data from the 14 highest enrolling sites of the Quality Outcomes Database CSM module. They compared 3-level anterior cervical discectomy and fusion (ACDF) and posterior cervical laminectomy and fusion (PCF) surgical procedures, excluding surgical procedures crossing the cervicothoracic junction. Rates of reaching the minimal clinically important difference (MCID) in patient-reported outcomes (PROs) were compared at 24 months postoperatively. Multivariable analyses adjusted for potential confounders elucidated in univariable analysis. RESULTS: Overall, 199 patients met the inclusion criteria: 123 ACDF (61.8%) and 76 PCF (38.2%) patients. The 24-month follow-up rates were similar (ACDF 90.2% vs PCF 92.1%, p = 0.67). Preoperatively, ACDF patients were younger (60.8 ± 10.2 vs 65.0 ± 10.3 years, p < 0.01), and greater proportions were privately insured (56.1% vs 36.8%, p = 0.02), actively employed (39.8% vs 22.8%, p = 0.04), and independently ambulatory (14.6% vs 31.6%, p < 0.01). Otherwise, the cohorts had equivalent baseline modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), numeric rating scale (NRS)-arm pain, NRS-neck pain, and EQ-5D scores (p > 0.05). ACDF patients had reduced hospitalization length (1.6 vs 3.9 days, p < 0.01) and a greater proportion had nonroutine discharge (7.3% vs 22.8%, p < 0.01), but they had a higher rate of postoperative dysphagia (13.5% vs 3.5%, p = 0.049). Compared with baseline values, both groups demonstrated improvements in all outcomes at 24 months (p < 0.05). In multivariable analyses, after controlling for age, insurance payor, employment status, ambulation status, and other potential clinically relevant confounders, ACDF was associated with a greater proportion of patients with maximum satisfaction on the North American Spine Society Patient Satisfaction Index (NASS) (NASS score of 1) at 24 months (69.4% vs 53.7%, OR 2.44, 95% CI 1.17-5.09, adjusted p = 0.02). Otherwise, the cohorts shared similar 24-month outcomes in terms of reaching the MCID for mJOA, NDI, NRS-arm pain, NRS-neck pain, and EQ-5D score (adjusted p > 0.05). There were no differences in the 3-month readmission (ACDF 4.1% vs PCF 3.9%, p = 0.97) and 24-month reoperation (ACDF 13.5% vs PCF 18.6%, p = 0.36) rates. CONCLUSIONS: In a cohort limited to 3-level fusion surgical procedures, ACDF was associated with reduced blood loss, shorter hospitalization length, and higher routine home discharge rates; however, PCF resulted in lower rates of postoperative dysphagia. The procedures yielded comparably significant improvements in functional status (mJOA score), neck and arm pain, neck pain-related disability, and quality of life at 3, 12, and 24 months. ACDF patients had significantly higher odds of maximum satisfaction (NASS score 1). Given comparable outcomes, patients should be counseled on each approach's complication profile to aid in surgical decision-making.

Greater improvement in Neck Disability Index scores in women after surgery for cervical myelopathy: an analysis of the Quality Outcomes Database.

OBJECTIVE: There is a high prevalence of cervical myelopathy that requires surgery; as such, it is important to identify how different groups benefit from surgery. The American Association of Neurological Surgeons launched the Quality Outcomes Database (QOD), a prospective longitudinal registry, that includes demographic, clinical, and patient-reported outcome data to measure the safety and quality of neurosurgical procedures. In this study, the authors assessed the impact of gender on patient-reported outcomes in patients who underwent surgery for cervical myelopathy. METHODS: The authors analyzed 1152 patients who underwent surgery for cervical myelopathy and were included in the QOD cervical module. Univariate comparison of baseline patient characteristics between males and females who underwent surgery for cervical spondylotic myelopathy was performed. Baseline characteristics that significantly differed between males and females were included in a multivariate generalized linear model comparing baseline and 1-year postoperative Neck Disability Index (NDI) scores. RESULTS: This study included 546 females and 604 males. Females demonstrated significantly greater improvement in NDI score 1 year after surgery (p = 0.036). In addition to gender, the presence of axial neck pain and insurance status were also significantly predictive of improvement in NDI score after surgery (p = 0.0013 and p = 0.0058, respectively). CONCLUSIONS: Females were more likely to benefit from surgery for cervical myelopathy compared with males. It is important to identify gender differences in postoperative outcomes after surgery in order to deliver more personalized and patient-centric care.

Which supervised machine learning algorithm can best predict achievement of minimum clinically important difference in neck pain after surgery in patients with cervical myelopathy? A QOD study.

OBJECTIVE: The purpose of this study was to evaluate the performance of different supervised machine learning algorithms to predict achievement of minimum clinically important difference (MCID) in neck pain after surgery in patients with cervical spondylotic myelopathy (CSM). METHODS: This was a retrospective analysis of the prospective Quality Outcomes Database CSM cohort. The data set was divided into an 80% training and a 20% test set. Various supervised learning algorithms (including logistic regression, support vector machine, decision tree, random forest, extra trees, gaussian naïve Bayes, k-nearest neighbors, multilayer perceptron, and extreme gradient boosted trees) were evaluated on their performance to predict achievement of MCID in neck pain at 3 and 24 months after surgery, given a set of predicting baseline features. Model performance was assessed with accuracy, F1 score, area under the receiver operating characteristic curve, precision, recall/sensitivity, and specificity. RESULTS: In total, 535 patients (46.9%) achieved MCID for neck pain at 3 months and 569 patients (49.9%) achieved it at 24 months. In each follow-up cohort, 501 patients (93.6%) were satisfied at 3 months after surgery and 569 patients (100%) were satisfied at 24 months after surgery. Of the supervised machine learning algorithms tested, logistic regression demonstrated the best accuracy (3 months: 0.76 ± 0.031, 24 months: 0.773 ± 0.044), followed by F1 score (3 months: 0.759 ± 0.019, 24 months: 0.777 ± 0.039) and area under the receiver operating characteristic curve (3 months: 0.762 ± 0.027, 24 months: 0.773 ± 0.043) at predicting achievement of MCID for neck pain at both follow-up time points, with fair performance. The best precision was also demonstrated by logistic regression at 3 (0.724 ± 0.058) and 24 (0.780 ± 0.097) months. The best recall/sensitivity was demonstrated by multilayer perceptron at 3 months (0.841 ± 0.094) and by extra trees at 24 months (0.817 ± 0.115). Highest specificity was shown by support vector machine at 3 months (0.952 ± 0.013) and by logistic regression at 24 months (0.747 ± 0.18). CONCLUSIONS: Appropriate selection of models for studies should be based on the strengths of each model and the aims of the studies. For maximally predicting true achievement of MCID in neck pain, of all the predictions in this balanced data set the appropriate metric for the authors' study was precision. For both short- and long-term follow-ups, logistic regression demonstrated the highest precision of all models tested. Logistic regression performed consistently the best of all models tested and remains a powerful model for clinical classification tasks.

Quality Outcomes Database Spine Care Project 2012-2020: milestones achieved in a collaborative North American outcomes registry to advance value-based spine care and evolution to the American Spine Registry.

The Quality Outcomes Database (QOD), formerly known as the National Neurosurgery Quality Outcomes Database (N2QOD), was established by the NeuroPoint Alliance (NPA) in collaboration with relevant national stakeholders and experts. The overarching goal of this project was to develop a centralized, nationally coordinated effort to allow individual surgeons and practice groups to collect, measure, and analyze practice patterns and neurosurgical outcomes. Specific objectives of this registry program were as follows: "1) to establish risk-adjusted national benchmarks for both the safety and effectiveness of neurosurgical procedures, 2) to allow practice groups and hospitals to analyze their individual morbidity and clinical outcomes in real time, 3) to generate both quality and efficiency data to support claims made to public and private payers and objectively demonstrate the value of care to other stakeholders, 4) to demonstrate the comparative effectiveness of neurosurgical and spine procedures, 5) to develop sophisticated 'risk models' to determine which subpopulations of patients are most likely to benefit from specific surgical interventions, and 6) to facilitate essential multicenter trials and other cooperative clinical studies." The NPA has launched several neurosurgical specialty modules in the QOD program in the 7 years since its inception including lumbar spine, cervical spine, and spinal deformity and cerebrovascular and intracranial tumor. The QOD Spine modules, which are the primary subject of this paper, have evolved into the largest North American spine registries yet created and have resulted in unprecedented cooperative activities within our specialty and among affiliated spine care practitioners. Herein, the authors discuss the experience of QOD Spine programs to date, with a brief description of their inception, some of the key achievements and milestones, as well as the recent transition of the spine modules to the American Spine Registry (ASR), a collaboration between the American Association of Neurological Surgeons and the American Academy of Orthopaedic Surgeons (AAOS).

Correlation of return to work with patient satisfaction after surgery for lumbar spondylolisthesis: an analysis of the Quality Outcomes Database.

OBJECTIVE: Return to work (RTW) and satisfaction are important outcome measures after surgery for degenerative spine disease. The authors queried the prospective Quality Outcomes Database (QOD) to determine if RTW correlated with patient satisfaction. METHODS: The QOD was queried for patients undergoing surgery for degenerative lumbar spondylolisthesis. The primary outcome of interest was correlation between RTW and patient satisfaction, as measured by the North American Spine Society patient satisfaction index (NASS). Secondarily, data on satisfied patients were analyzed to see what patient factors correlated with RTW. RESULTS: Of 608 total patients in the QOD spondylolisthesis data set, there were 292 patients for whom data were available on both satisfaction and RTW status. Of these, 249 (85.3%) were satisfied with surgery (NASS score 1-2), and 224 (76.7%) did RTW after surgery. Of the 68 patients who did not RTW after surgery, 49 (72.1%) were still satisfied with surgery. Of the 224 patients who did RTW, 24 (10.7%) were unsatisfied with surgery (NASS score 3-4). There were significantly more people who had an NASS score of 1 in the RTW group than in the non-RTW group (71.4% vs 42.6%, p < 0.05). Failure to RTW was associated with lower level of education, worse baseline back pain (measured with a numeric rating scale), and worse baseline disability (measured with the Oswestry Disability Index [ODI]). CONCLUSIONS: There are a substantial number of patients who are satisfied with surgery even though they did not RTW. Patients who were satisfied with surgery and did not RTW typically had worse preoperative back pain and ODI and typically did not have a college education. While RTW remains an important measure after surgery, physicians should be mindful that patients who do not RTW may still be satisfied with their outcome.

Predictive model for long-term patient satisfaction after surgery for grade I degenerative lumbar spondylolisthesis: insights from the Quality Outcomes Database.

OBJECTIVESince 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.METHODSThe 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.RESULTSA 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.CONCLUSIONSCurrent 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.

A comparison of minimally invasive transforaminal lumbar interbody fusion and decompression alone for degenerative lumbar spondylolisthesis.

OBJECTIVEThe optimal minimally invasive surgery (MIS) approach for grade 1 lumbar spondylolisthesis is not clearly elucidated. In this study, the authors compared the 24-month patient-reported outcomes (PROs) after MIS transforaminal lumbar interbody fusion (TLIF) and MIS decompression for degenerative lumbar spondylolisthesis.METHODSA total of 608 patients from 12 high-enrolling sites participating in the Quality Outcomes Database (QOD) lumbar spondylolisthesis module underwent single-level surgery for degenerative grade 1 lumbar spondylolisthesis, of whom 143 underwent MIS (72 MIS TLIF [50.3%] and 71 MIS decompression [49.7%]). Surgeries were classified as MIS if there was utilization of percutaneous screw fixation and placement of a Wiltse plane MIS intervertebral body graft (MIS TLIF) or if there was a tubular decompression (MIS decompression). Parameters obtained at baseline through at least 24 months of follow-up were collected. PROs included the Oswestry Disability Index (ODI), numeric rating scale (NRS) for back pain, NRS for leg pain, EuroQol-5D (EQ-5D) questionnaire, and North American Spine Society (NASS) satisfaction questionnaire. Multivariate models were constructed to adjust for patient characteristics, surgical variables, and baseline PRO values.RESULTSThe mean age of the MIS cohort was 67.1 ± 11.3 years (MIS TLIF 62.1 years vs MIS decompression 72.3 years) and consisted of 79 (55.2%) women (MIS TLIF 55.6% vs MIS decompression 54.9%). The proportion in each cohort reaching the 24-month follow-up did not differ significantly between the cohorts (MIS TLIF 83.3% and MIS decompression 84.5%, p = 0.85). MIS TLIF was associated with greater blood loss (mean 108.8 vs 33.0 ml, p < 0.001), longer operative time (mean 228.2 vs 101.8 minutes, p < 0.001), and longer length of hospitalization (mean 2.9 vs 0.7 days, p < 0.001). MIS TLIF was associated with a significantly lower reoperation rate (14.1% vs 1.4%, p = 0.004). Both cohorts demonstrated significant improvements in ODI, NRS back pain, NRS leg pain, and EQ-5D at 24 months (p < 0.001, all comparisons relative to baseline). In multivariate analyses, MIS TLIF-as opposed to MIS decompression alone-was associated with superior ODI change (ß = -7.59, 95% CI -14.96 to -0.23; p = 0.04), NRS back pain change (ß = -1.54, 95% CI -2.78 to -0.30; p = 0.02), and NASS satisfaction (OR 0.32, 95% CI 0.12-0.82; p = 0.02).CONCLUSIONSFor symptomatic, single-level degenerative spondylolisthesis, MIS TLIF was associated with a lower reoperation rate and superior outcomes for disability, back pain, and patient satisfaction compared with posterior MIS decompression alone. This finding may aid surgical decision-making when considering MIS for degenerative lumbar spondylolisthesis.

Women fare best following surgery for degenerative lumbar spondylolisthesis: a comparison of the most and least satisfied patients utilizing data from the Quality Outcomes Database.

OBJECTIVE The American Association of Neurological Surgeons launched the Quality Outcomes Database (QOD), a prospective longitudinal registry that includes demographic, clinical, and patient-reported outcome (PRO) data, to measure the safety and quality of neurosurgical procedures, including spinal surgery. Differing results from recent randomized controlled trials have established a need to clarify the groups that would most benefit from surgery for degenerative lumbar spondylolisthesis. In the present study, the authors compared patients who were the most and the least satisfied following surgery for degenerative lumbar spondylolisthesis. METHODS This was a retrospective analysis of a prospective, national longitudinal registry including patients who had undergone surgery for grade 1 degenerative lumbar spondylolisthesis. The most and least satisfied patients were identified based on an answer of "1" and "4," respectively, on the North American Spine Society (NASS) Satisfaction Questionnaire 12 months postoperatively. Baseline demographics, clinical variables, surgical parameters, and outcomes were collected. Patient-reported outcome measures, including the Numeric Rating Scale (NRS) for back pain, NRS for leg pain, Oswestry Disability Index (ODI), and EQ-5D (the EuroQol health survey), were administered at baseline and 3 and 12 months after treatment. RESULTS Four hundred seventy-seven patients underwent surgery for grade 1 degenerative lumbar spondylolisthesis in the period from July 2014 through December 2015. Two hundred fifty-five patients (53.5%) were the most satisfied and 26 (5.5%) were the least satisfied. Compared with the most satisfied patients, the least satisfied ones more often had coronary artery disease (CAD; 26.9% vs 12.2%, p = 0.04) and had higher body mass indices (32.9 ± 6.5 vs 30.0 ± 6.0 kg/m2, p = 0.02). In the multivariate analysis, female sex (OR 2.9, p = 0.02) was associated with the most satisfaction. Notably, the American Society of Anesthesiologists (ASA) class, smoking, psychiatric comorbidity, and employment status were not significantly associated with satisfaction. Although there were no significant differences at baseline, the most satisfied patients had significantly lower NRS back and leg pain and ODI scores and a greater EQ-5D score at 3 and 12 months postoperatively (p < 0.001 for all). CONCLUSIONS This study revealed that some patient factors differ between those who report the most and those who report the least satisfaction after surgery for degenerative lumbar spondylolisthesis. Patients reporting the least satisfaction tended to have CAD or were obese. Female sex was associated with the most satisfaction when adjusting for potential covariates. These findings highlight several key factors that could aid in setting expectations for outcomes following surgery for degenerative lumbar spondylolisthesis.

Impact of educational background on preoperative disease severity and postoperative outcomes among patients with lumbar spondylolisthesis: a Quality Outcomes Database study.

OBJECTIVE: Deficiency in patient education has been correlated with increased disease-related morbidity and decreased access to care. However, the associations between educational level, preoperative disease severity, and postoperative outcomes in patients with lumbar spondylolisthesis have yet to be explored. METHODS: The spondylolisthesis dataset of the Quality Outcomes Database (QOD)-a cohort with prospectively collected data by the SpineCORe study team of the 12 highest enrolling sites with an 81% follow-up at 5 years -was utilized and stratified for educational level. Patients were classified into three categories (high school or less, graduate, or postgraduate). Patient-reported outcome measures (PROMs) documented at baseline and follow-up included Oswestry Disability Index (ODI) score, EQ-5D in quality-adjusted life years, and numeric rating scale (NRS) scores for back and leg pain. Disease severity was measured with PROMs. Postoperatively, patients also completed the North American Spine Society assessment to measure their satisfaction with surgery. Multivariable regression analysis was used to compare education level with disease severity and postoperative outcomes. RESULTS: A total of 608 patients underwent analysis, with 260 individuals (42.8%) at an educational level of high school or less. On univariate analysis, baseline disease severity was worse among patients with lower levels of education. On multivariable regression analysis, patients with postgraduate level of education had significantly lower ODI scores (ß = -3.75, 95% CI -7.31 to -0.2, p = 0.039) compared to graduates, while the other PROMs were not associated with significant differences at baseline. Five years postoperatively, patients from various educational backgrounds exhibited similar rates of minimal clinically important differences in PROMs. Nevertheless, patients with the lowest educational level had higher ODI scores (27.1, p < 0.01), lower EQ-5D scores (0.701, p < 0.01), and higher NRS leg pain (3.0, p < 0.01) and back pain (4.0, p < 0.01) scores compared to those with graduate or postgraduate levels of education. The odds for postoperative satisfaction were also comparable between cohorts at 5 years (reference, graduate level; high school or less, OR 0.87, 95% CI 0.46-1.64, p = 0.659; postgraduate, OR 1.6, 95% CI 0.7-3.65, p = 0.262). CONCLUSIONS: Lower patient education level was associated with a greater baseline disease severity in patients with lumbar spondylolisthesis. Surgery demonstrated similar benefits irrespective of educational background; however, individuals with lower educational level reported lower outcomes overall. This emphasizes the need for enhanced health literacy to mitigate disparities for reported outcomes.

Predictors of Delayed Clinical Benefit Following Surgical Treatment for Low Grade Spondylolisthesis.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To investigate what factors predict delayed improvement after surgical treatment of low grade spondylolisthesis. SUMMARY OF BACKGROUND DATA: Lumbar surgery leads to clinical improvement in the majority of patients with low grade spondylolisthesis. Most patients improve rapidly after surgery, but some patients demonstrate a delayed clinical course. METHODS: The Quality and Outcomes Database (QOD) was queried for grade 1 spondylolisthesis patients who underwent surgery who had patient reported outcome measures (PROMs) collected at baseline, 3-, 6- and 12-months, including back and leg pain numeric rating scale (NRS), Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). Patients were stratified as "Early responders" reaching MCID at 3 months and maintaining improvement through 12 months and "Delayed responders" not reaching MCID at 3 months but ultimately reaching MCID at 12 months. These two groups were compared with respect to factors which predicted delayed improvement. RESULTS: Of 608 patients enrolled, 436 (72%) met inclusion criteria for this study. Overall, 317 patients (72.7%) reached MCID for ODI at 12 months following surgery. Of these patients, 249 (78.5%) exhibited a rapid clinical improvement trajectory and had achieved ODI MCID threshold by the 3-month postop follow-up. 68 patients (21.4%) showed a delayed trajectory, and had not achieved ODI MCID threshold at 3 months, but did ultimately reach MCID at 12-month follow-up. Factors associated with delayed improvement included impaired preoperative ambulatory status, better baseline back and leg pain scores, and worse 3-month leg pain scores (P<0.01). CONCLUSIONS: The majority of patients undergoing surgery for low grade spondylolisthesis reach ODI MCID threshold rapidly, within the first three months after surgery. Factors associated with a delayed clinical course include impaired preoperative ambulation status, relatively better preoperative back and leg pain, and persistent leg pain at 3 months.

Is Upper Extremity or Lower Extremity Function More Important for Patient Satisfaction? An Analysis of 24-Month Outcomes from the QOD Cervical Spondylotic Myelopathy Cohort.

STUDY DESIGN: Retrospective analysis of a prospective, multicenter registry. OBJECTIVE: To assess whether upper or lower limb mJOA improvement more strongly associates with patient satisfaction after surgery for cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: The modified Japanese Orthopaedic Association (mJOA) is commonly used to assess functional status in patients with CSM. Patients present with upper and/or lower extremity dysfunction, and it is unclear whether improvement in one and/or both symptoms drives postoperative patient satisfaction. METHODS: This study utilizes the prospective Quality Outcomes Database (QOD) CSM data set. Clinical outcomes included mJOA and North American Spine Society (NASS) satisfaction. The upper limb mJOA score was defined as upper motor plus sensory mJOA, and the lower limb mJOA as lower motor plus sensory mJOA. Ordered logistic regression was used to determine whether upper or lower limb mJOA was more closely associated with NASS satisfaction, adjusting for other covariates. RESULTS: Overall, 1141 patients were enrolled in the QOD CSM cohort. In all, 780 had both preoperative and 24-month mJOA scores, met inclusion criteria, and were included for analysis. The baseline mJOA was 12.1±2.7, and postoperatively, 85.6% would undergo surgery again (NASS 1 or 2, satisfied). Patients exhibited mean improvement in both upper (baseline:3.9±1.4 vs. 24 mo:5.0±1.1, P<0.001) and lower limb mJOA (baseline:3.9±1.4 vs. 24 mon:4.5±1.5, P<0.001); however, the 24-month change in the upper limb mJOA was greater (upper:1.1±1.6 vs. lower:0.6±1.6, P<0.001). Across 24-month NASS satisfaction, the baseline upper and lower limb mJOA scores were similar (pupper=0.28, plower=0.092). However, as satisfaction decreased, the 24-month change in upper and lower limb mJOA decreased as well (pupper<0.001, plower<0.001). Patients with NASS scores of 4 (lowest satisfaction) did not demonstrate significant differences from baseline in upper or lower limb mJOA (P>0.05). In ordered logistic regression, NASS satisfaction was independently associated with upper limb mJOA improvement (OR=0.81; 95% CI: 0.68-0.97; P=0.019) but not lower limb mJOA improvement (OR=0.84; 95% CI: 0.70-1.0; P=0.054). CONCLUSIONS: As the magnitude of upper and lower mJOA improvement decreased postoperatively, so too did patient satisfaction with surgical intervention. Upper limb mJOA improvement was a significant independent predictor of patient satisfaction, whereas lower limb mJOA improvement was not. These findings may aid preoperative counseling, stratified by patients' upper and lower extremity treatment expectations. LEVEL OF EVIDENCE: Level-III.

Predictors of patient satisfaction after surgery for grade 1 degenerative spondylolisthesis: a 5-year analysis of the Quality Outcomes Database.

OBJECTIVE: Lumbar decompression and/or fusion surgery is a common operation for symptomatic lumbar spondylolisthesis refractory to conservative management. Multiyear follow-up of patient outcomes can be difficult to obtain but allows for identification of preoperative patient characteristics associated with durable pain relief, improved functional outcome, and higher patient satisfaction. METHODS: A query of the Quality Outcomes Database (QOD) low-grade spondylolisthesis module for patients who underwent surgery for grade 1 lumbar spondylolisthesis (from July 2014 to June 2016 at the 12 highest-enrolling sites) was used to identify patient satisfaction, as measured with the North American Spine Society (NASS) questionnaire, which uses a scale of 1-4. Patients were considered satisfied if they had a score ≤ 2. Multivariable logistic regression was performed to identify baseline demographic and clinical predictors of long-term satisfaction 5 years after surgery. RESULTS: Of 573 eligible patients from a cohort of 608, patient satisfaction data were available for 81.2%. Satisfaction (NASS score of 1 or 2) was reported by 389 patients (83.7%) at 5-year follow-up. Satisfied patients were predominantly White and ambulation independent and had lower baseline BMI, lower back pain levels, lower Oswestry Disability Index (ODI) scores, and greater EQ-5D index scores at baseline when compared to the unsatisfied group. No significant differences in reoperation rates between groups were reported at 5 years. On multivariate analysis, patients who were independently ambulating at baseline had greater odds of long-term satisfaction (OR 1.12, p = 0.04). Patients who had higher 5-year ODI scores (OR 0.99, p < 0.01) and were uninsured (OR 0.43, p = 0.01) were less likely to report long-term satisfaction. CONCLUSIONS: Lumbar surgery for the treatment of grade 1 spondylolisthesis can provide lasting pain relief with high patient satisfaction. Baseline independent ambulation is associated with a higher long-term satisfaction rate after surgery. Higher ODI scores at 5-year follow-up and uninsured status are associated with lower postoperative long-term satisfaction.

Does comorbid depression and anxiety portend poor long-term outcomes following surgery for lumbar spondylolisthesis? Five-year analysis of the Quality Outcomes Database.

OBJECTIVE: Depression and anxiety are associated with poor outcomes following spine surgery. However, the influence of these conditions on achieving a minimal clinically important difference (MCID) following lumbar spine surgery, as well as the potential compounding effects of comorbid depression and anxiety, is not well understood. This study explores the impact of comorbid depression and anxiety on long-term clinical outcomes following surgical treatment for degenerative lumbar spondylolisthesis. METHODS: This study was a retrospective analysis of the multicenter, prospectively collected Quality Outcomes Database (QOD). Patients with surgically treated grade 1 lumbar spondylolisthesis from 12 centers were included. Preoperative baseline characteristics and comorbidities were recorded, including self-reported depression and/or anxiety. Pre- and postoperative patient-reported outcomes (PROs) were recorded: the numeric rating scale (NRS) score for back pain (NRS-BP), NRS score for leg pain (NRS-LP), Oswestry Disability Index (ODI), and EQ-5D. Patients were grouped into 3 cohorts: no self-reported depression or anxiety (non-SRD/A), self-reported depression or anxiety (SRD/A), or presence of both comorbidities (SRD+A). Changes in PROs over time, satisfaction rates, and rates of MCID were compared. A multivariable regression analysis was performed to establish independent associations. RESULTS: Of the 608 patients, there were 452 (74.3%) with non-SRD/A, 81 (13.3%) with SRD/A, and 75 (12.3%) with SRD+A. Overall, 91.8% and 80.4% of patients had ≥ 24 and ≥ 60 months of follow-up, respectively. Baseline PROs were universally inferior for the SRD+A cohort. However, at 60-month follow-up, changes in all PROs were greatest for the SRD+A cohort, resulting in nonsignificant differences in absolute NRS-BP, NRS-LP, ODI, and EQ-5D across the 3 groups. MCID was achieved for the SRD+A cohort at similar rates to the non-SRD/A cohort. All groups achieved > 80% satisfaction rates with surgery without significant differences across the cohorts (p = 0.79). On multivariable regression, comorbid depression and anxiety were associated with worse baseline PROs, but they had no impact on 60-month PROs or 60-month achievement of MCIDs. CONCLUSIONS: Despite lower baseline PROs, patients with comorbid depression and anxiety achieved comparable rates of MCID and satisfaction after surgery for lumbar spondylolisthesis to those without either condition. This quality-of-life benefit was durable at 5-year follow-up. These data suggest that patients with self-reported comorbid depression and anxiety should not be excluded from consideration of surgical intervention and often substantially benefit from surgery.

Does diabetes affect outcome or reoperation rate after lumbar decompression or arthrodesis? A matched analysis of the Quality Outcomes Database data set.

OBJECTIVE: Diabetes mellitus (DM) is a known risk factor for postsurgical and systemic complications after lumbar spinal surgery. Smaller studies have also demonstrated diminished improvements in patient-reported outcomes (PROs), with increased reoperation and readmission rates after lumbar surgery in patients with DM. The authors aimed to examine longer-term PROs in patients with DM undergoing lumbar decompression and/or arthrodesis for degenerative pathology. METHODS: The Quality Outcomes Database was queried for patients undergoing elective lumbar decompression and/or arthrodesis for degenerative pathology. Patients were grouped into DM and non-DM groups and optimally matched in a 1:1 ratio on 31 baseline variables, including the number of operated levels. Outcomes of interest were readmissions and reoperations at 30 and 90 days after surgery in addition to improvements in Oswestry Disability Index, back pain, and leg pain scores and quality-adjusted life-years at 90 days after surgery. RESULTS: The matched decompression cohort comprised 7836 patients (3236 [41.3] females) with a mean age of 63.5 ± 12.6 years, and the matched arthrodesis cohort comprised 7336 patients (3907 [53.3%] females) with a mean age of 64.8 ± 10.3 years. In patients undergoing lumbar decompression, no significant differences in nonroutine discharge, length of stay (LOS), readmissions, reoperations, and PROs were observed. In patients undergoing lumbar arthrodesis, nonroutine discharge (15.7% vs 13.4%, p < 0.01), LOS (3.2 ± 2.0 vs 3.0 ± 3.5 days, p < 0.01), 30-day (6.5% vs 4.4%, p < 0.01) and 90-day (9.1% vs 7.0%, p < 0.01) readmission rates, and the 90-day reoperation rate (4.3% vs 3.2%, p = 0.01) were all significantly higher in the DM group. For DM patients undergoing lumbar arthrodesis, subgroup analyses demonstrated a significantly higher risk of poor surgical outcomes with the open approach. CONCLUSIONS: Patients with and without DM undergoing lumbar spinal decompression alone have comparable readmission and reoperation rates, while those undergoing arthrodesis procedures have a higher risk of poor surgical outcomes up to 90 days after surgery. Surgeons should target optimal DM control preoperatively, particularly for patients undergoing elective lumbar arthrodesis.

What factors influence surgical decision-making in anterior versus posterior surgery for cervical myelopathy? A QOD analysis.

OBJECTIVE: The aim of this study was to explore the preoperative patient characteristics that affect surgical decision-making when selecting an anterior or posterior operative approach in patients diagnosed with cervical spondylotic myelopathy (CSM). METHODS: This was a multi-institutional, retrospective study of the prospective Quality Outcomes Database (QOD) Cervical Spondylotic Myelopathy module. Patients aged 18 years or older diagnosed with primary CSM who underwent multilevel (≥ 2-level) elective surgery were included. Demographics and baseline clinical characteristics were collected. RESULTS: Of the 841 patients with CSM in the database, 492 (58.5%) underwent multilevel anterior surgery and 349 (41.5%) underwent multilevel posterior surgery. Surgeons more often performed a posterior surgical approach in older patients (mean 64.8 ± 10.6 vs 58.5 ± 11.1 years, p < 0.001) and those with a higher American Society of Anesthesiologists class (class III or IV: 52.4% vs 46.3%, p = 0.003), a higher rate of motor deficit (67.0% vs 58.7%, p = 0.014), worse myelopathy (mean modified Japanese Orthopaedic Association score 11.4 ± 3.1 vs 12.4 ± 2.6, p < 0.001), and more levels treated (4.3 ± 1.3 vs 2.4 ± 0.6, p < 0.001). On the other hand, surgeons more frequently performed an anterior surgical approach when patients were employed (47.2% vs 23.2%, p < 0.001) and had intervertebral disc herniation as an underlying pathology (30.7% vs 9.2%, p < 0.001). CONCLUSIONS: The selection of approach for patients with CSM depends on patient demographics and symptomology. Posterior surgery was performed in patients who were older and had worse systemic disease, increased myelopathy, and greater levels of stenosis. Anterior surgery was more often performed in patients who were employed and had intervertebral disc herniation.

Do class III obese patients achieve similar outcomes and satisfaction to nonobese patients following surgery for cervical myelopathy? A QOD study.

OBJECTIVE: The aim of this study was to compare the rate of achievement of the minimal clinically important difference (MCID) in patient-reported outcomes (PROs) and satisfaction between cervical spondylotic myelopathy (CSM) patients with and without class III obesity who underwent surgery. METHODS: The authors analyzed patients from the 14 highest-enrolling sites in the prospective Quality Outcomes Database CSM cohort. Patients were dichotomized based on whether or not they were obese (class III, BMI ≥ 35 kg/m2). PROs including visual analog scale (VAS) neck and arm pain, Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), EQ-5D, and North American Spine Society patient satisfaction scores were collected at baseline and 24 months after cervical spine surgery. RESULTS: Of the 1141 patients with CSM who underwent surgery, 230 (20.2%) were obese and 911 (79.8%) were not. The 24-month follow-up rate was 87.4% for PROs. Patients who were obese were younger (58.1 ± 12.1 years vs 61.2 ± 11.6 years, p = 0.001), more frequently female (57.4% vs 44.9%, p = 0.001), and African American (22.6% vs 13.4%, p = 0.002) and had a lower education level (high school or less: 49.1% vs 40.8%, p = 0.002) and a higher American Society of Anesthesiologists grade (2.7 ± 0.5 vs 2.5 ± 0.6, p < 0.001). Clinically at baseline, the obese group had worse neck pain (VAS score: 5.7 ± 3.2 vs 5.1 ± 3.3), arm pain (VAS score: 5.4 ± 3.5 vs 4.8 ± 3.5), disability (NDI score: 42.7 ± 20.4 vs 37.4 ± 20.7), quality of life (EQ-5D score: 0.54 ± 0.22 vs 0.56 ± 0.22), and function (mJOA score: 11.6 ± 2.8 vs 12.2 ± 2.8) (all p < 0.05). At the 24-month follow-up, however, there was no difference in the change in PROs between the two groups. Even after accounting for relevant covariates, no significant difference in achievement of MCID and satisfaction was observed between the two groups at 24 months. CONCLUSIONS: Despite the class III obese group having worse baseline clinical presentations, the two cohorts achieved similar rates of satisfaction and MCID in PROs. Class III obesity should not preclude and/or delay surgical management for patients who would otherwise benefit from surgery for CSM.

Predictors of patient satisfaction in the surgical treatment of cervical spondylotic myelopathy.

OBJECTIVE: Patients with cervical spondylotic myelopathy (CSM) experience progressive neurological impairment. Surgical intervention is often pursued to halt neurological symptom progression and allow for recovery of function. In this paper, the authors explore predictors of patient satisfaction following surgical intervention for CSM. METHODS: This is a retrospective review of prospectively collected data from the multicenter Quality Outcomes Database. Patients who underwent surgical intervention for CSM with a minimum follow-up of 2 years were included. Patient-reported satisfaction was defined as a North American Spine Society (NASS) satisfaction score of 1 or 2. Patient demographics, surgical parameters, and outcomes were assessed as related to patient satisfaction. Patient quality of life scores were measured at baseline and 24-month time points. Univariate regression analyses were performed using the chi-square test or Student t-test to assess patient satisfaction measures. Multivariate logistic regression analysis was conducted to assess for factors predictive of postoperative satisfaction at 24 months. RESULTS: A total of 1140 patients at 14 institutions with CSM who underwent surgical intervention were included, and 944 completed a patient satisfaction survey at 24 months postoperatively. The baseline modified Japanese Orthopaedic Association (mJOA) score was 12.0 ± 2.8. A total of 793 (84.0%) patients reported satisfaction (NASS score 1 or 2) after 2 years. Male and female patients reported similar satisfaction rates (female sex: 47.0% not satisfied vs 48.5% satisfied, p = 0.73). Black race was associated with less satisfaction (26.5% not satisfied vs 13.2% satisfied, p < 0.01). Baseline psychiatric comorbidities, obesity, and length of stay did not correlate with 24-month satisfaction. Crossing the cervicothoracic junction did not affect satisfactory scores (p = 0.19), and minimally invasive approaches were not associated with increased patient satisfaction (p = 0.14). Lower baseline numeric rating scale neck pain scores (5.03 vs 5.61, p = 0.04) and higher baseline mJOA scores (12.28 vs 11.66, p = 0.01) were associated with higher satisfaction rates. CONCLUSIONS: Surgical treatment of CSM results in a high rate of patient satisfaction (84.0%) at the 2-year follow-up. Patients with milder myelopathy report higher satisfaction rates, suggesting that intervention earlier in the disease process may result in greater long-term satisfaction.