Harrell, Frank E.

Study Design. Retrospective analysis of prospectively collected registry data. Objective. To develop and validate prediction models for 12-month patient-reported outcomes of disability, pain, and myelopathy in patients undergoing elective cervical spine surgery. Summary of Background Data. Predictive models have the potential to be utilized preoperatively to set expectations, adjust modifiable characteristics, and provide a patient-centered model of care. Methods. This study was conducted using data from the cervical module of the Quality Outcomes Database. The outcomes of interest were disability (Neck Disability Index:), pain (Numeric Rating Scale), and modified Japanese Orthopaedic Association score for myelopathy. Multivariable proportional odds ordinal regression models were developed for patients with cervical radiculopathy and myelopathy. Patient demographic, clinical, and surgical covariates as well as baseline patient-reported outcomes scores were included in all models. The models were internally validated using bootstrap resampling to estimate the likely performance on a new sample of patients. Results. Four thousand nine hundred eighty-eight patients underwent surgery for radiculopathy and 2641 patients for myelopathy. The most important predictor of poor postoperative outcomes at 12-months was the baseline Neck Disability Index score for patients with radiculopathy and modified Japanese Orthopaedic Association score for patients with myelopathy. In addition, symptom duration, workers’ compensation, age, employment, and ambulatory and smoking status had a statistically significant impact on all outcomes (P < 0.001). Clinical and surgical variables contributed very little to predictive models, with posterior approach being associated with higher odds of having worse 12-month outcome scores in both the radiculopathy and myelopathy cohorts (P < 0.001). The full models overall discriminative performance ranged from 0.654 to 0.725. Conclusions. These predictive models provide individualized risk-adjusted estimates of 12-month disability, pain, and myelopathy outcomes for patients undergoing spine surgery for degenerative cervical disease. Predictive models have the potential to be used as a shared decision-making tool for evidence-based preoperative counselling. Level of Evidence: 2.

OBJECTIVE Patient satisfaction with treatment outcome is gaining an increasingly important role in assessing the value of surgical spine care delivery. Nationwide data evaluating the predictors of patient satisfaction in elective cervical spine surgery are lacking. The authors sought to decipher the impacts of the patient, surgical practice, and surgeon on satisfaction with outcome following anterior cervical discectomy and fusion (ACDF). METHODS The authors queried the Quality Outcomes Database for patients undergoing 1- to 2-level ACDF for degenerative spine disease since 2013. Patient satisfaction with the surgical outcome as measured by the North American Spine Society (NASS) scale comprised the primary outcome. A multivariable proportional odds logistic regression model was constructed with adjustments for baseline patient characteristics and surgical practice and surgeon characteristics as fixed effects. RESULTS A total of 4148 patients (median age 54 years, 48% males) with complete 12-month NASS satisfaction data were analyzed. Sixty-seven percent of patients answered that “surgery met their expectations” (n = 2803), while 20% reported that they “did not improve as much as they had hoped but they would undergo the same operation for the same results” (n = 836). After adjusting for a multitude of patient-specific as well as hospital- and surgeon-related factors, the authors found baseline Neck Disability Index (NDI) score, US geographic region of hospital, patient race, insurance status, symptom duration, and Workers’ compensation status to be the most important predictors of patient satisfaction. The discriminative ability of the model was satisfactory (c-index 0.66, overfitting-corrected estimate 0.64). CONCLUSIONS The authors’ results found baseline NDI score, patient race, insurance status, symptom duration, and Workers’ compensation status as well as the geographic region of the hospital to be the most important predictors of long-term patient satisfaction after a 1- to 2-level ACDF. The findings of the present analysis further reinforce the role of preoperative discussion with patients on setting treatment goals and realistic expectations.

Abstract BACKGROUND Modern healthcare reforms focus on identifying and measuring the quality and value of care. Patient satisfaction is particularly important in the management of degenerative cervical radiculopathy (DCR) since it leads to significant neck pain and disability primarily affecting the patients’ quality of life. OBJECTIVE To determine the association of baseline and 12-mo Neck Disability Index (NDI) with patient satisfaction after elective surgery for DCR. METHODS The Quality Outcomes Database cervical module was queried for patients who underwent elective surgery for DCR. A multivariable proportional odds regression model was fitted with 12-mo satisfaction as the outcome. The covariates for this model included patients’ demographics, surgical characteristics, and baseline and 12-mo patient reported outcomes (PROs). Wald-statistics were calculated to determine the relative importance of each independent variable for 12-mo patient satisfaction. RESULTS The analysis included 2206 patients who underwent elective surgery for DCR. In multivariable analysis, after adjusting for baseline and surgery specific variables, the 12-mo NDI score showed the highest association with 12-mo satisfaction (Waldχ2-df = 99.17, 58.1% of total χ2). The level of satisfaction increases with decrease in 12-mo NDI score regardless of the baseline NDI score. CONCLUSION Our study identifies 12-mo NDI score as a very influential driver of 12-mo patient satisfaction after surgery for DCR. In addition, there are lesser contributions from other 12-mo PROs, baseline Numeric Rating Scale for arm pain and American Society of Anesthesiologists (ASA) grade. The baseline level of disability was found to be irrelevant to patients. They seemed to only value their current level of disability, compared to baseline, in rating satisfaction with surgical outcome.

Study Design. This study retrospectively analyzes prospectively collected data. Objective. Here, we aim to determine the influence of preoperative and 12-month modified Japanese Orthopedic Association (mJOA) on satisfaction and understand the change in mJOA severity classification after surgical management of degenerative cervical myelopathy (DCM). Summary of Background Data. DCM is a progressive degenerative spine disease resulting from cervical cord compression. The natural progression of DCM is variable; some patients experience periods of stability, while others rapidly deteriorate following disease onset. The mJOA is commonly used to grade and categorize myelopathy symptoms, but its association with postoperative satisfaction has not been previously explored. Methods. The quality and outcomes database (QOD) was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9 to 13), or severe (<9) categories on the mJOA scores. A McNemar–Bowker test was used to assess whether a significant proportion of patients changed mJOA category between preoperative and 12 months postoperative. A multivariable proportional odds ordinal logistic regression model was fitted with 12-month satisfaction as the outcome of interest. Results. We identified 1963 patients who underwent elective surgery for DCM and completed 12-months follow-ups. Comparing mJOA severity level preoperatively and at 12 months revealed that 55% remained in the same category, 37% improved, and 7% moved to a worse category. After adjusting for baseline and surgery-specific variables, the 12-month mJOA category had the highest impact on patient satisfaction (P < 0.001). Conclusion. Patient satisfaction is an indispensable tool for measuring quality of care after spine surgery. In this sample, 12-month mJOA category, regardless of preop mJOA, was significantly correlated with satisfaction. Given these findings, it is important to advise patients of the probability that surgery will change their mJOA severity classification and the changes required to achieve postoperative satisfaction. Level of Evidence: 3

Study Design. This study retrospectively analyzes prospectively collected data. Objective. The primary aim of this study is to present a scheme for patient-reported outcome (PRO)-based, risk-adjusted rankings of spine surgeons and sites that perform elective lumbar surgery, using the Quality and Outcomes Database (QOD). Summary of Background Data. There is currently no means of determining which spine surgeons or centers are positive or negative outliers with respect to PROs for elective lumbar surgery. This is a critical gap as we move toward a value-based model of health care in which providers assume more accountability for the effectiveness of their treatments. Methods. Random effects regression models were fit for the following outcomes, with QOD site as a fixed effect but surgeon ID as a random effect: Oswestry Disability Index, EQ-5D, back pain and leg pain, and satisfaction. Hierarchical Bayesian models were also fit for each outcome, with QOD site as a random effect and surgeon as a nested random effect. Results. Our study cohort consists of 8834 patients who underwent surgery by 124 QOD surgeons, for the degenerative lumbar diseases. Nonoverlapping Bayesian credible intervals demonstrate that the variance attributed to QOD site was greater than the nested variance attributed to surgeon ID for the included PROs. Conclusion. This study presents a novel strategy for the risk-adjusted, PRO-based ranking of spine surgeons and practices. This can help identify positive and negative outliers, thereby forming the basis for large-scale quality improvement. Assuming adequate coverage of baseline risk adjustment, the choice of surgeon matters when considering PROs after lumbar surgery; however, the choice of site appears to matter more. Level of Evidence: 3

Study Design. This study retrospectively analyzes prospectively collected data. Objective. Here we aim to develop predictive models for 3-month medical and surgical readmission after elective lumbar surgery, based on a multi-institutional, national spine registry. Summary of Background Data. Unplanned readmissions place considerable stress on payers, hospitals, and patients. Medicare data reveals a 30-day readmission rate of 7.8% for lumbar-decompressions and 13.0% for lumbar-fusions, and hospitals are now being penalized for excessive 30-day readmission rates by virtue of the Hospital Readmissions Reduction Program. Methods. The Quality and Outcomes Database (QOD) was queried for patients undergoing elective lumbar surgery for degenerative diseases. The QOD prospectively captures 3-month readmissions through electronic medical record (EMR) review and self-reported outcome questionnaires. Distinct multivariable logistic regression models were fitted for surgery-related and medical readmissions adjusting for patient and surgery-specific variables. Results. Of the total 33,674 patients included in this study 2079 (6.15%) reported at least one readmission during the 90-day postoperative period. The odds of medical readmission were significantly higher for older patients, males versus females, African Americans versus Caucasion, those with higher American Society of Anesthesiologists (ASA) grade, diabetes, coronary artery disease, higher numbers of involved levels, anterior only or anterior–posterior versus posterior approach; also, for patients who were unemployed compared with employed patients and those with high baseline Oswestry Disability Index (ODI). The odds of surgery-related readmission were significantly greater for patients with a higher body mass index (BMI), a higher ASA grade, female versus male, and African Americans versus Caucasians; also, for patients with severe depression, more involved spinal levels, anterior-only surgical approaches and higher baseline ODI scores. Conclusion. In this study we present internally validated predictive models for medical and surgical readmission after elective lumbar spine surgery. These findings set the stage for targeted interventions with a potential to reduce unnecessary readmissions, and also suggest that medical and surgical readmissions be treated as distinct clinical events. Level of Evidence: 3

Abstract BACKGROUND Reducing length of stay (LOS) in a safe manner has the potential to save significant costs for the care of patients undergoing elective lumbar spine surgery. Due to the relative absence on weekends of staff required for discharging patients to rehabilitation or nursing facilities, we hypothesize that patients undergoing lumbar surgery later in the week have a longer LOS than their counterparts. OBJECTIVE To analyze the effect of day of the week for lumbar surgery on LOS. METHODS Patients undergoing surgery for lumbar degenerative disease were prospectively enrolled in the multicenter quality and outcomes database registry. A multivariable proportional odds regression model was built with LOS as the outcome of interest and patient and surgical variables as covariates. RESULTS A total of 11 897 patients were analyzed. Among those discharged home, the regression analysis demonstrated significantly higher odds of longer LOS for patients undergoing surgery on Friday as compared to Monday ( P < .001). Among those discharged to a facility, there were significantly higher odds of longer LOS for patients undergoing surgery on Wednesday ( P < .001), Thursday ( P < .001), and Friday ( P = .002) as compared to Monday. CONCLUSION The findings of this study suggest that lumbar patients undergoing fusions and those discharged to a facility have longer LOS when surgery is later in the week. Scheduling these patients for surgery earlier in the week and ensuring adequate resources for patient disposition on weekends may lead to LOS reduction and cost savings for hospitals, payers, and patients alike.

Abstract BACKGROUND The choice of anterior vs posterior approach for degenerative cervical myelopathy that spans multiple segments remains controversial. OBJECTIVE To compare the outcomes following the 2 approaches using multicenter prospectively collected data. METHODS Quality Outcomes Database (QOD) for patients undergoing surgery for 3 to 5 level degenerative cervical myelopathy was analyzed. The anterior group (anterior cervical discectomy [ACDF] or corpectomy [ACCF] with fusion) was compared with posterior cervical fusion. Outcomes included: patient reported outcomes (PROs): neck disability index (NDI), numeric rating scale (NRS) of neck pain and arm pain, EQ-5D, modified Japanese Orthopedic Association score for myelopathy (mJOA), and NASS satisfaction questionnaire; hospital length of stay (LOS), 90-d readmission, and return to work (RTW). Multivariable regression models were fitted for outcomes. RESULTS Of total 245 patients analyzed, 163 patients underwent anterior surgery (ACDF-116, ACCF-47) and 82 underwent posterior surgery. Patients undergoing an anterior approach had lower odds of having higher LOS ( P < .001, odds ratio 0.16, 95% confidence interval 0.08-0.30). The 12-mo NDI, EQ-5D, NRS, mJOA, and satisfaction scores as well as 90-d readmission and RTW did not differ significantly between anterior and posterior groups. CONCLUSION Patients undergoing anterior approaches for 3 to 5 level degenerative cervical myelopathy had shorter hospital LOS compared to those undergoing posterior decompression and fusion. Also, patients in both groups exhibited similar long-term PROs, readmission, and RTW rates. Further investigations are needed to compare the differences in longer term reoperation rates and functional outcomes before the clinical superiority of one approach over the other can be established.

OBJECTIVEIn this analysis the authors compare the characteristics of smokers to nonsmokers using demographic, socioeconomic, and comorbidity variables. They also investigate which of these characteristics are most strongly associated with smoking status. Finally, the authors investigate whether the association between known patient risk factors and disability outcome is differentially modified by patient smoking status for those who have undergone surgery for lumbar degeneration.METHODSA total of 7547 patients undergoing degenerative lumbar surgery were entered into a prospective multicenter registry (Quality Outcomes Database [QOD]). A retrospective analysis of the prospectively collected data was conducted. Patients were dichotomized as smokers (current smokers) and nonsmokers. Multivariable logistic regression analysis fitted for patient smoking status and subsequent measurement of variable importance was performed to identify the strongest patient characteristics associated with smoking status. Multivariable linear regression models fitted for 12-month Oswestry Disability Index (ODI) scores in subsets of smokers and nonsmokers was performed to investigate whether differential effects of risk factors by smoking status might be present.RESULTSIn total, 18% (n = 1365) of patients were smokers and 82% (n = 6182) were nonsmokers. In a multivariable logistic regression analysis, the factors significantly associated with patients’ smoking status were sex (p < 0.0001), age (p < 0.0001), body mass index (p < 0.0001), educational status (p < 0.0001), insurance status (p < 0.001), and employment/occupation (p = 0.0024). Patients with diabetes had lowers odds of being a smoker (p = 0.0008), while patients with coronary artery disease had greater odds of being a smoker (p = 0.044). Patients’ propensity for smoking was also significantly associated with higher American Society of Anesthesiologists (ASA) class (p < 0.0001), anterior-alone surgical approach (p = 0.018), greater number of levels (p = 0.0246), decompression only (p = 0.0001), and higher baseline ODI score (p < 0.0001). In a multivariable proportional odds logistic regression model, the adjusted odds ratio of risk factors and direction of improvement in 12-month ODI scores remained similar between the subsets of smokers and nonsmokers.CONCLUSIONSUsing a large, national, multiinstitutional registry, the authors described the profile of patients who undergo lumbar spine surgery and its association with their smoking status. Compared with nonsmokers, smokers were younger, male, nondiabetic, nonobese patients presenting with leg pain more so than back pain, with higher ASA classes, higher disability, less education, more likely to be unemployed, and with Medicaid/uninsured insurance status. Smoking status did not affect the association between these risk factors and 12-month ODI outcome, suggesting that interventions for modifiable risk factors are equally efficacious between smokers and nonsmokers.