Christopher I. Shaffrey
John R. W. Kestle
Scott A. Meyer and Praveen V. Mummaneni
Kaisorn L. Chaichana, Scott L. Parker, Alessandro Olivi and Alfredo Quiñones-Hinojosa
Seizures are a common presenting symptom and cause of morbidity for patients with malignant astrocytomas. The authors set out to determine preoperative seizure characteristics, effects of surgery on seizure control, and factors associated with prolonged seizure control in patients with malignant astrocytomas.
Cases involving adult patients who underwent primary resection of a hemispheric anaplastic astrocytoma (AA) or glioblastoma multiforme (GBM) at the Johns Hopkins Medical Institutions between 1996 and 2006 were retrospectively reviewed. Multivariate logistical regression analysis was used to identify associations with pre-operative seizures, and multivariate proportional hazards regression analyses were used to identify associations with prolonged seizure control following resection.
Of the 648 patients (505 with GBM, 143 with AA) in this series, 153 (24%) presented with seizures. The factors more commonly associated with preoperative seizures were AA pathology (p = 0.03), temporal lobe involvement (p = 0.04), and cortical location (p = 0.04), while the factors less commonly associated with preoperative seizures were greater age (p = 0.03) and larger tumor size (p ≤ 0.001). Among those patients with a history of seizures, outcome 12 months after surgery was Engel Class I (seizure free) in 77%, Class II (rare seizures) in 12%, Class III (meaningful improvement) in 6%, and Class IV (no improvement) in 5%. Postoperative seizures were rare in patients without a history of preoperative seizures. The factor positively associated with prolonged seizure control was increased Karnofsky Performance Scale score (p = 0.002), while the factors negatively associated with seizure control were preoperative uncontrolled seizures (p = 0.03) and parietal lobe involvement (p = 0.005). Seizure recurrence in patients with postoperative seizure control was independently associated with tumor recurrence (p = 0.006).
The identification and consideration of factors associated with prolonged seizure control may help guide treatment strategies aimed at improving the quality of life for patients with malignant astrocytomas.
John R. W. Kestle
Scott L. Parker, David N. Shau, Stephen K. Mendenhall and Matthew J. McGirt
Revision lumbar fusion procedures are technically challenging and can be associated with tremendous health care resource utilization and cost. There is a paucity of data regarding specific factors that significantly contribute to increased cost of care. In light of this, the authors set out to identify independent risk factors predictive of increasing 2-year direct health care costs after revision lumbar fusion.
One hundred fifty patients undergoing revision instrument-assisted fusion for adjacent-segment disease (50 cases), pseudarthrosis (47 cases), or same-level stenosis (53 cases) were included in this study. Patient demographics, comorbidities, preoperative health states as assessed by patient-reported outcome questionnaires and perioperative complications were collected and analyzed. Two-year back-related medical resource utilization and direct health care costs were assessed. The independent association of all variables to increasing cost was assessed using multivariate linear regression analysis.
There was a wide range ($24,935–$63,769) in overall 2-year direct costs for patients undergoing revision lumbar fusion (mean $32,915 ± $8344 [± SD]). Preoperative variables independently associated with 2-year direct health care costs included diagnosis of congestive heart failure, more severe leg pain (visual analog scale), greater back-related disability (Oswestry Disability Index), and worse mental health (12-Item Short Form Health Survey Mental Component Summary score). There was a 1.1- to 1.2-fold increase in cost for patients in the greatest quartiles compared with those in the lowest quartiles for these variables. Surgical site infection, return to the operating room, and spine-related hospital readmission during the 90-day global health period were postoperative variables independently associated with 2-year cost. Patients in the greatest versus lowest quartiles had a 1.7- to 1.9-fold increase in cost for these variables.
Revision lumbar fusion can be associated with considerable 2-year health care costs. These costs can also vary widely among patients, as evidenced by the 2.6-fold overall cost range in this series. Although comorbidities and preoperative severity of disease states contribute to cost of care, the primary drivers of increased cost include perioperative complications such as surgical site infection, return to the operating room, and readmission during the global health period. Measures focused on health service improvement will be most successful in reducing the cost of care for patients undergoing revision lumbar fusion.
Matthew J. McGirt, Saniya S. Godil, Anthony L. Asher, Scott L. Parker and Clinton J. Devin
In an era of escalating health care cost and universal pressure of improving efficiency and cost of care, ambulatory surgery centers (ASCs) have emerged as lower cost options for many surgical therapies. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed and is rapidly increasing with an expanding aging population. While ASCs offer cost advantages for ACDF, there is a scarcity of evidence that ASCs allow for equivalent quality and thus superior health care value. Therefore, the authors analyzed a nationwide, prospective quality improvement registry (National Surgical Quality Improvement Program [NSQIP]) to compare the quality of ACDF surgery performed in the outpatient ASC versus the inpatient hospital setting.
Patients undergoing ACDF (2005-2011) were identified from the NSQIP database based on the primary Current Procedural Terminology codes. Patients were divided into 2 cohorts (outpatient vs inpatient) based on the acute care setting documented in the NSQIP database. All 30-day surgical morbidity and mortality rates were compared between the 2 groups. Propensity score matching and multivariate logistic regression analysis were used to adjust for confounding factors and to identify the independent association of outpatient ACDF with perioperative outcomes and morbidity.
A total of 7288 ACDF cases were identified (inpatient = 6120, outpatient = 1168). Unadjusted rates of major morbidity (0.94% vs 4.5%, p < 0.001) and return to the operating room (OR) within 30 days (0.3% vs 2.0%, p < 0.001) were significantly lower in outpatient versus inpatient ACDF. After propensity matching 1442 cases (inpatient = 650, outpatient = 792) based on baseline 32 covariates, rates of major morbidity (1.4% vs 3.1%, p = 0.03), and return to the OR (0.34% vs 1.4%, p = 0.04) remained significantly lower after outpatient ACDF. Adjusted comparison using multivariate logistic regression demonstrated that ACDF performed in the outpatient setting had 58% lower odds of having a major morbidity and 80% lower odds of return to the OR within 30 days.
An analysis of a nationwide, prospective quality improvement registry representing more than 250 hospitals demonstrates that 1- to 2-level ACDF can be safely performed in the outpatient ambulatory surgery setting in patients who are appropriate candidates. In an effort to decrease cost of care, surgeons can safely consider performing ACDF in an ASC environment.
Scott L. Parker, Anthony L. Asher, Saniya S. Godil, Clinton J. Devin and Matthew J. McGirt
The health care landscape is rapidly shifting to incentivize quality of care rather than quantity of care. Quality and outcomes registry platforms lie at the center of all emerging evidence-driven reform models and will be used to inform decision makers in health care delivery. Obtaining real-world registry outcomes data from patients 12 months after spine surgery remains a challenge. The authors set out to determine whether 3-month patient-reported outcomes accurately predict 12-month outcomes and, hence, whether 3-month measurement systems suffice to identify effective versus noneffective spine care.
All patients undergoing lumbar spine surgery for degenerative disease at a single medical institution over a 2-year period were enrolled in a prospective longitudinal registry. Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12], EQ-5D, and the Zung Self-Rating Depression Scale) were recorded prospectively at baseline and at 3 months and 12 months after surgery. Linear regression was performed to determine the independent association of 3- and 12-month outcome. Receiver operating characteristic (ROC) curve analysis was performed to determine whether improvement in general health state (EQ-5D) and disability (ODI) at 3 months accurately predicted improvement and achievement of minimum clinical important difference (MCID) at 12 months.
A total of 593 patients undergoing elective lumbar surgery were included in the study. There was a significant correlation between 3-month and 12-month EQ-5D (r = 0.71; p < 0.0001) and ODI (r = 0.70; p < 0.0001); however, the authors observed a sizable discrepancy in achievement of a clinically significant improvement (MCID) threshold at 3 versus 12 months on an individual patient level. For postoperative disability (ODI), 11.5% of patients who achieved an MCID threshold at 3 months dropped below this threshold at 12 months; 10.5% of patients who did not meet the MCID threshold at 3 months continued to improve and ultimately surpassed the MCID threshold at 12 months. For ODI, achieving MCID at 3 months accurately predicted 12-month MCID with only 62.6% specificity and 86.8% sensitivity. For postoperative health utility (EQ-5D), 8.5% of patients lost an MCID threshold improvement from 3 months to 12 months, while 4.0% gained the MCID threshold between 3 and 12 months postoperatively. For EQ-5D (quality-adjusted life years), achieving MCID at 3 months accurately predicted 12-month MCID with only 87.7% specificity and 87.2% sensitivity.
In a prospective registry, patient-reported measures of treatment effectiveness obtained at 3 months correlated with 12-month measures overall in aggregate, but did not reliably predict 12-month outcome at the patient level. Many patients who do not benefit from surgery by 3 months do so by 12 months, and, conversely, many patients reporting meaningful improvement by 3 months report loss of benefit at 12 months. Prospective longitudinal spine outcomes registries need to span at least 12 months to identify effective versus noneffective patient care.
Oren N. Gottfried, Scott L. Parker, Ibrahim Omeis, Ali Bydon, Ziya L. Gokaslan and Jean-Paul Wolinsky
Cervical spondylolysis is an uncommon disorder involving a cleft at the pars interarticularis. It is most often found at the C-6 level, and clinical presentations have included incidental radiographic findings, neck pain, and rarely neurological compromise. Although subaxial cervical spondylolysis has been described in 150 patients, defects at the C-2 pedicles are rare.
The authors present 2 new cases of C-2 spondylolysis in athletically active young persons who did not demonstrate instability or neurological deficits, were able to remain active, and are being managed conservatively with serial examinations and imaging. They also discuss the results of 22 previously reported cases of C-2 spondylolysis. Based on the literature and their own experience, the authors conclude that most patients with C-2 spondylolysis remain neurologically intact, maintain stability despite the bony defect, and can be managed conservatively. Surgery is reserved for patients who demonstrate severe instability or spinal cord compromise due to stenosis.
Scott L. Parker, Ahilan Sivaganesan, Silky Chotai, Matthew J. McGirt, Anthony L. Asher and Clinton J. Devin
Hospital readmissions lead to a significant increase in the total cost of care in patients undergoing elective spine surgery. Understanding factors associated with an increased risk of postoperative readmission could facilitate a reduction in such occurrences. The aims of this study were to develop and validate a predictive model for 90-day hospital readmission following elective spine surgery.
All patients undergoing elective spine surgery for degenerative disease were enrolled in a prospective longitudinal registry. All 90-day readmissions were prospectively recorded. For predictive modeling, all covariates were selected by choosing those variables that were significantly associated with readmission and by incorporating other relevant variables based on clinical intuition and the Akaike information criterion. Eighty percent of the sample was randomly selected for model development and 20% for model validation. Multiple logistic regression analysis was performed with Bayesian model averaging (BMA) to model the odds of 90-day readmission. Goodness of fit was assessed via the C-statistic, that is, the area under the receiver operating characteristic curve (AUC), using the training data set. Discrimination (predictive performance) was assessed using the C-statistic, as applied to the 20% validation data set.
A total of 2803 consecutive patients were enrolled in the registry, and their data were analyzed for this study. Of this cohort, 227 (8.1%) patients were readmitted to the hospital (for any cause) within 90 days postoperatively. Variables significantly associated with an increased risk of readmission were as follows (OR [95% CI]): lumbar surgery 1.8 [1.1–2.8], government-issued insurance 2.0 [1.4–3.0], hypertension 2.1 [1.4–3.3], prior myocardial infarction 2.2 [1.2–3.8], diabetes 2.5 [1.7–3.7], and coagulation disorder 3.1 [1.6–5.8]. These variables, in addition to others determined a priori to be clinically relevant, comprised 32 inputs in the predictive model constructed using BMA. The AUC value for the training data set was 0.77 for model development and 0.76 for model validation.
Identification of high-risk patients is feasible with the novel predictive model presented herein. Appropriate allocation of resources to reduce the postoperative incidence of readmission may reduce the readmission rate and the associated health care costs.