The NeuroPoint alliance SRS & tumor QOD registries.

OBJECTIVE: Along with the increasing interest in real-world evidence in neuro-oncology, the deficiencies of prior population-based and quality registries became evident. The neuro-oncological quality registries of the NeuroPoint Alliance (NPA) focus on neuro-oncological surgery and stereotactic radiosurgery (SRS) and aim to fill the gaps of neuro-oncological practice in quality surveillance and real-world research. METHODS: Herein, we discuss the historical background, design process, and features of the NPA SRS and Tumor QOD registries. The registries'current status and future directions are outlined. RESULTS: The NPA SRS and Tumor QOD registries were designed based on the principles of prospective multi-institutional data collection, central auditing for data quality, and focus on patient-reported outcomes (PROs). Currently, the registries include over 4,500 and 2,500 patients each, with caseloads comprising predominantly of brain metastases and primary extra-axial tumors, respectively. The registries serve both as a quality surveillance and improvement tool - providing participating sites with adjusted quality reports - and as platforms for real-world research of observational and, potentially, interventional nature. Future directions of the NPA neuro-oncological registries include the functional communications of the two registries and the incorporation of imaging analyses in the workflow of quality assessment and research efforts. CONCLUSIONS: The NPA SRS and Tumor QOD registries are quality registries of unique granularity in terms of surgical variables and postoperative outcomes. They constitute increasingly valuable data sources for real-time quality surveillance of participating sites and real-world research.

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.

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.

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.

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).

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.

A predictive model and nomogram for predicting return to work at 3 months after cervical spine surgery: an analysis from the Quality Outcomes Database.

OBJECTIVEBack pain and neck pain are two of the most common causes of work loss due to disability, which poses an economic burden on society. Due to recent changes in healthcare policies, patient-centered outcomes including return to work have been increasingly prioritized by physicians and hospitals to optimize healthcare delivery. In this study, the authors used a national spine registry to identify clinical factors associated with return to work at 3 months among patients undergoing a cervical spine surgery.METHODSThe authors queried the Quality Outcomes Database registry for information collected from April 2013 through March 2017 for preoperatively employed patients undergoing cervical spine surgery for degenerative spine disease. Covariates included demographic, clinical, and operative variables, and baseline patient-reported outcomes. Multiple imputations were used for missing values and multivariable logistic regression analysis was used to identify factors associated with higher odds of returning to work. Bootstrap resampling (200 iterations) was used to assess the validity of the model. A nomogram was constructed using the results of the multivariable model.RESULTSA total of 4689 patients were analyzed, of whom 82.2% (n = 3854) returned to work at 3 months postoperatively. Among previously employed and working patients, 89.3% (n = 3443) returned to work compared to 52.3% (n = 411) among those who were employed but not working (e.g., were on a leave) at the time of surgery (p < 0.001). On multivariable logistic regression the authors found that patients who were less likely to return to work were older (age > 56-65 years: OR 0.69, 95% CI 0.57-0.85, p < 0.001; age > 65 years: OR 0.65, 95% CI 0.43-0.97, p = 0.02); were employed but not working (OR 0.24, 95% CI 0.20-0.29, p < 0.001); were employed part time (OR 0.56, 95% CI 0.42-0.76, p < 0.001); had a heavy-intensity (OR 0.42, 95% CI 0.32-0.54, p < 0.001) or medium-intensity (OR 0.59, 95% CI 0.46-0.76, p < 0.001) occupation compared to a sedentary occupation type; had workers' compensation (OR 0.38, 95% CI 0.28-0.53, p < 0.001); had a higher Neck Disability Index score at baseline (OR 0.60, 95% CI 0.51-0.70, p = 0.017); were more likely to present with myelopathy (OR 0.52, 95% CI 0.42-0.63, p < 0.001); and had more levels fused (3-5 levels: OR 0.46, 95% CI 0.35-0.61, p < 0.001). Using the multivariable analysis, the authors then constructed a nomogram to predict return to work, which was found to have an area under the curve of 0.812 and good validity.CONCLUSIONSReturn to work is a crucial outcome that is being increasingly prioritized for employed patients undergoing spine surgery. The results from this study could help surgeons identify at-risk patients so that preoperative expectations could be discussed more comprehensively.

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.

Defining the minimum clinically important difference for grade I degenerative lumbar spondylolisthesis: insights from the Quality Outcomes Database.

OBJECTIVE Patient-reported outcomes (PROs) play a pivotal role in defining the value of surgical interventions for spinal disease. The concept of minimum clinically important difference (MCID) is considered the new standard for determining the effectiveness of a given treatment and describing patient satisfaction in response to that treatment. The purpose of this study was to determine the MCID associated with surgical treatment for degenerative lumbar spondylolisthesis. METHODS The authors queried the Quality Outcomes Database registry from July 2014 through December 2015 for patients who underwent posterior lumbar surgery for grade I degenerative spondylolisthesis. Recorded PROs included scores on the Oswestry Disability Index (ODI), EQ-5D, and numeric rating scale (NRS) for leg pain (NRS-LP) and back pain (NRS-BP). Anchor-based (using the North American Spine Society satisfaction scale) and distribution-based (half a standard deviation, small Cohen's effect size, standard error of measurement, and minimum detectable change [MDC]) methods were used to calculate the MCID for each PRO. RESULTS A total of 441 patients (80 who underwent laminectomies alone and 361 who underwent fusion procedures) from 11 participating sites were included in the analysis. The changes in functional outcome scores between baseline and the 1-year postoperative evaluation were as follows: 23.5 ± 17.4 points for ODI, 0.24 ± 0.23 for EQ-5D, 4.1 ± 3.5 for NRS-LP, and 3.7 ± 3.2 for NRS-BP. The different calculation methods generated a range of MCID values for each PRO: 3.3-26.5 points for ODI, 0.04-0.3 points for EQ-5D, 0.6-4.5 points for NRS-LP, and 0.5-4.2 points for NRS-BP. The MDC approach appeared to be the most appropriate for calculating MCID because it provided a threshold greater than the measurement error and was closest to the average change difference between the satisfied and not-satisfied patients. On subgroup analysis, the MCID thresholds for laminectomy-alone patients were comparable to those for the patients who underwent arthrodesis as well as for the entire cohort. CONCLUSIONS The MCID for PROs was highly variable depending on the calculation technique. The MDC seems to be a statistically and clinically sound method for defining the appropriate MCID value for patients with grade I degenerative lumbar spondylolisthesis. Based on this method, the MCID values are 14.3 points for ODI, 0.2 points for EQ-5D, 1.7 points for NRS-LP, and 1.6 points for NRS-BP.

Variability in the utility of predictive models in predicting patient-reported outcomes following spine surgery for degenerative conditions: a systematic review.

OBJECTIVEThere is increasing emphasis on patient-reported outcomes (PROs) to quantitatively evaluate quality outcomes from degenerative spine surgery. However, accurate prediction of PROs is challenging due to heterogeneity in outcome measures, patient characteristics, treatment characteristics, and methodological characteristics. The purpose of this study was to evaluate the current landscape of independently validated predictive models for PROs in elective degenerative spinal surgery with respect to study design and model generation, training, accuracy, reliability, variance, and utility.METHODSThe authors analyzed the current predictive models in PROs by performing a search of the PubMed and Ovid databases using PRISMA guidelines and a PICOS (participants, intervention, comparison, outcomes, study design) model. They assessed the common outcomes and variables used across models as well as the study design and internal validation methods.RESULTSA total of 7 articles met the inclusion criteria, including a total of 17 validated predictive models of PROs after adult degenerative spine surgery. National registry databases were used in 4 of the studies. Validation cohorts were used in 2 studies for model verification and 5 studies used other methods, including random sample bootstrapping techniques. Reported c-index values ranged from 0.47 to 0.79. Two studies report the area under the curve (0.71-0.83) and one reports a misclassification rate (9.9%). Several positive predictors, including high baseline pain intensity and disability, demonstrated high likelihood of favorable PROs.CONCLUSIONSA limited but effective cohort of validated predictive models of spine surgical outcomes had proven good predictability for PROs. Instruments with predictive accuracy can enhance shared decision-making, improve rehabilitation, and inform best practices in the setting of heterogeneous patient characteristics and surgical factors.

Minimally invasive versus open fusion for Grade I degenerative lumbar spondylolisthesis: analysis of the Quality Outcomes Database.

OBJECTIVE Lumbar spondylolisthesis is a degenerative condition that can be surgically treated with either open or minimally invasive decompression and instrumented fusion. Minimally invasive surgery (MIS) approaches may shorten recovery, reduce blood loss, and minimize soft-tissue damage with resultant reduced postoperative pain and disability. METHODS The authors queried the national, multicenter Quality Outcomes Database (QOD) registry for patients undergoing posterior lumbar fusion between July 2014 and December 2015 for Grade I degenerative spondylolisthesis. The authors recorded baseline and 12-month patient-reported outcomes (PROs), including Oswestry Disability Index (ODI), EQ-5D, numeric rating scale (NRS)-back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society satisfaction questionnaire). Multivariable regression models were fitted for hospital length of stay (LOS), 12-month PROs, and 90-day return to work, after adjusting for an array of preoperative and surgical variables. RESULTS A total of 345 patients (open surgery, n = 254; MIS, n = 91) from 11 participating sites were identified in the QOD. The follow-up rate at 12 months was 84% (83.5% [open surgery]; 85% [MIS]). Overall, baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts. Two hundred fifty seven patients underwent 1-level fusion (open surgery, n = 181; MIS, n = 76), and 88 patients underwent 2-level fusion (open surgery, n = 73; MIS, n = 15). Patients in both groups reported significant improvement in all primary outcomes (all p < 0.001). MIS was associated with a significantly lower mean intraoperative estimated blood loss and slightly longer operative times in both 1- and 2-level fusion subgroups. Although the LOS was shorter for MIS 1-level cases, this was not significantly different. No difference was detected with regard to the 12-month PROs between the 1-level MIS versus the 1-level open surgical groups. However, change in functional outcome scores for patients undergoing 2-level fusion was notably larger in the MIS cohort for ODI (-27 vs -16, p = 0.1), EQ-5D (0.27 vs 0.15, p = 0.08), and NRS-BP (-3.5 vs -2.7, p = 0.41); statistical significance was shown only for changes in NRS-LP scores (-4.9 vs -2.8, p = 0.02). On risk-adjusted analysis for 1-level fusion, open versus minimally invasive approach was not significant for 12-month PROs, LOS, and 90-day return to work. CONCLUSIONS Significant improvement was found in terms of all functional outcomes in patients undergoing open or MIS fusion for lumbar spondylolisthesis. No difference was detected between the 2 techniques for 1-level fusion in terms of patient-reported outcomes, LOS, and 90-day return to work. However, patients undergoing 2-level MIS fusion reported significantly better improvement in NRS-LP at 12 months than patients undergoing 2-level open surgery. Longer follow-up is needed to provide further insight into the comparative effectiveness of the 2 procedures.

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.

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.

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 the number of social factors affect long-term patient-reported outcomes and satisfaction in those with cervical myelopathy? A QOD study.

OBJECTIVE: It is not clear whether there is an additive effect of social factors in keeping patients with cervical spondylotic myelopathy (CSM) from achieving both a minimum clinically important difference (MCID) in outcomes and satisfaction after surgery. The aim of this study was to explore the effect of multiple social factors on postoperative outcomes and satisfaction. METHODS: This was a multiinstitutional, retrospective study of the prospective Quality Outcomes Database (QOD) CSM cohort, which included patients aged 18 years or older who were diagnosed with primary CSM and underwent operative management. Social factors included race (White vs non-White), education (high school or below vs above), employment (employed vs not), and insurance (private vs nonprivate). Patients were considered to have improved from surgery if the following criteria were met: 1) they reported a score of 1 or 2 on the North American Spine Society index, and 2) they met the MCID in patient-reported outcomes (i.e., visual analog scale [VAS] neck and arm pain, Neck Disability Index [NDI], and EuroQol-5D [EQ-5D]). RESULTS: Of the 1141 patients included in the study, 205 (18.0%) had 0, 347 (30.4%) had 1, 334 (29.3%) had 2, and 255 (22.3%) had 3 social factors. The 24-month follow-up rate was > 80% for all patient-reported outcomes. After adjusting for all relevant covariates (p < 0.02), patients with 1 or more social factors were less likely to improve from surgery in all measured outcomes including VAS neck pain (OR 0.90, 95% CI 0.83-0.99) and arm pain (OR 0.88, 95% CI 0.80-0.96); NDI (OR 0.90, 95% CI 0.83-0.98); and EQ-5D (OR 0.90, 95% CI 0.83-0.97) (all p < 0.05) compared to those without any social factors. Patients with 2 social factors (outcomes: neck pain OR 0.86, arm pain OR 0.81, NDI OR 0.84, EQ-5D OR 0.81; all p < 0.05) or 3 social factors (outcomes: neck pain OR 0.84, arm pain OR 0.84, NDI OR 0.84, EQ-5D OR 0.84; all p < 0.05) were more likely to fare worse in all outcomes compared to those with only 1 social factor. CONCLUSIONS: Compared to those without any social factors, patients who had at least 1 social factor were less likely to achieve MCID and feel satisfied after surgery. The effect of social factors is additive in that patients with a higher number of factors are less likely to improve compared to those with only 1 social factor.

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.

Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study.

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD). METHODS: Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement-based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed. RESULTS: Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1-61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement-based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97-1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99-1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21-1.15), and the cost per QALY gained was $80,580. CONCLUSIONS: PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.

Leveraging machine learning to ascertain the implications of preoperative body mass index on surgical outcomes for 282 patients with preoperative obesity and lumbar spondylolisthesis in the Quality Outcomes Database.

OBJECTIVE: Prior studies have revealed that a body mass index (BMI) ≥ 30 is associated with worse outcomes following surgical intervention in grade 1 lumbar spondylolisthesis. Using a machine learning approach, this study aimed to leverage the prospective Quality Outcomes Database (QOD) to identify a BMI threshold for patients undergoing surgical intervention for grade 1 lumbar spondylolisthesis and thus reliably identify optimal surgical candidates among obese patients. METHODS: Patients with grade 1 lumbar spondylolisthesis and preoperative BMI ≥ 30 from the prospectively collected QOD lumbar spondylolisthesis module were included in this study. A 12-month composite outcome was generated by performing principal components analysis and k-means clustering on four validated measures of surgical outcomes in patients with spondylolisthesis. Random forests were generated to determine the most important preoperative patient characteristics in predicting the composite outcome. Recursive partitioning was used to extract a BMI threshold associated with optimal outcomes. RESULTS: The average BMI was 35.7, with 282 (46.4%) of the 608 patients from the QOD data set having a BMI ≥ 30. Principal components analysis revealed that the first principal component accounted for 99.2% of the variance in the four outcome measures. Two clusters were identified corresponding to patients with suboptimal outcomes (severe back pain, increased disability, impaired quality of life, and low satisfaction) and to those with optimal outcomes. Recursive partitioning established a BMI threshold of 37.5 after pruning via cross-validation. CONCLUSIONS: In this multicenter study, the authors found that a BMI ≤ 37.5 was associated with improved patient outcomes following surgical intervention. These findings may help augment predictive analytics to deliver precision medicine and improve prehabilitation strategies.