Risk factors for 30-day reoperation and 3-month readmission: analysis from the Quality and Outcomes Database lumbar spine registry

A Neurosurgical Readmissions Reduction Program in an Academic Hospital Leveraging Machine Learning, Workflow Analysis, and Simulation

BACKGROUND

 Predicting 30-day hospital readmissions is crucial for improving patient outcomes, optimizing resource allocation, and achieving financial savings. Existing studies reporting the development of machine learning (ML) models predictive of neurosurgical readmissions do not report factors related to clinical implementation.

OBJECTIVES

 Train individual predictive models with good performance (area under the receiver operating characteristic curve or AUROC > 0.8), identify potential interventions through semi-structured interviews, and demonstrate estimated clinical and financial impact of these models.

METHODS

 Electronic health records were utilized with five ML methodologies: gradient boosting, decision tree, random forest, ridge logistic regression, and linear support vector machine. Variables of interest were determined by domain experts and literature. The dataset was split divided 80% for training and validation and 20% for testing randomly. Clinical workflow analysis was conducted using semi-structured interviews to identify possible intervention points. Calibrated agent-based models (ABMs), based on a previous study with interventions, were applied to simulate reductions of the 30-day readmission rate and financial costs.

RESULTS

 The dataset covered 12,334 neurosurgical intensive care unit (NSICU) admissions (11,029 patients); 1,903 spine surgery admissions (1,641 patients), and 2,208 traumatic brain injury (TBI) admissions (2,185 patients), with readmission rate of 13.13, 13.93, and 23.73%, respectively. The random forest model for NSICU achieved best performance with an AUROC score of 0.89, capturing potential patients effectively. Six interventions were identified through 12 semi-structured interviews targeting preoperative, inpatient stay, discharge phases, and follow-up phases. Calibrated ABMs simulated median readmission reduction rates and resulted in 13.13 to 10.12% (NSICU), 13.90 to 10.98% (spine surgery), and 23.64 to 21.20% (TBI). Approximately $1,300,614.28 in saving resulted from potential interventions.

CONCLUSION

 This study reports the successful development and simulation of an ML-based approach for predicting and reducing 30-day hospital readmissions in neurosurgery. The intervention shows feasibility in improving patient outcomes and reducing financial losses.

Risk factors for early reoperation in patients after posterior lumbar interbody fusion surgery. A propensity-matched cohort analysis

BACKGROUND

Reoperation is usually associated with poor results and increased morbidity and hospital costs. However, the rates, causes, and risk factors for reoperation in patients undergoing lumbar spinal fusion surgery remain controversial. This study aimed to identify the risk factors for early reoperation after posterior lumbar interbody fusion surgery and to compare the clinical outcomes between patients who underwent reoperation and those who did not.

METHODS

We investigated a multicenter medical record database of 1263 patients who underwent posterior lumbar interbody fusion surgery between 2012 and 2015. A total of 72 (5.7%) reoperations within two years after surgery were identified and were propensity-matched for age, sex, number of fusion segments, and surgeon's experience.

RESULTS

We analyzed a total of 114 patients (57 who underwent reoperation (R group) and 57 who did not (C group)). The mean age was 62.6 ± 13.4 years, with 78 men and 36 women. The mean number of fused segments was 1.2 ± 0.5. Surgical site infection was the most common cause of reoperation. There were significant differences in the incidence of diabetes mellitus (p = 0.024), preoperative ambulation status (p = 0.046), and ASA grade (p < 0.001) between the C and R groups. The recovery rate of the Japanese Orthopaedic Association score was significantly lower in the R group compared to the C group (R: 50.5 ± 28.8%, C: 63.9 ± 33.7%, p = 0.024). There were significant differences in the bone fusion rate (R: 63.2%, C: 96.5%, p < 0.001) and incidence of screw loosening (R: 31.6%; C: 10.5%; p = 0.006).

CONCLUSION

Diabetes mellitus, preoperative ambulation status, and ASA grade were significant risk factors for early reoperation following posterior lumbar interbody fusion surgery. The patients who underwent early reoperation had worse clinical outcomes than those who did not.

30-and 90-day readmissions in lumbar spine surgery. Differences in prevalence and causes

BACKGROUND

The morbidity associated with surgical treatment of lumbar degenerative conditions has attracted increasing interest due to the economic impact on society, especially postoperative readmission. Limited studies have assessed this risk in a prospective, single-center consecutive fashion.

OBJECTIVE

To assess the incidence and causes of 30- and 90-day unplanned readmission and revision surgery following surgical treatment for lumbar degenerative spine conditions at a tertiary treatment center.

STUDY DESIGN

Prospective, single-center cohort study.

METHODS

All patients undergoing degenerative lumbar spine surgery in a 1-year period from February 1st, 2016, were prospectively included. Patient characteristics, surgical information and information regarding postoperative complications, including readmission (30- and 90-days) and revision surgery were recorded. Readmissions were classified according to whether they were due to the surgical intervention specifically, or a medical complication.

RESULTS

A total of 1399 patients underwent surgery for various lumbar degenerative pathologies in the study period and all were included. Of these, 9.4% (n = 132) were readmitted within 30 days of surgery and in some cases, multiple readmissions occurred (up to 3). The total 90-day readmission rate was 17.6%. Of these, 15% were related to the surgical procedure. The predominant medical related causes were systemic infection (30-day: 14.4%, 90-day: 10.7%), neurological symptoms (30-day: 6.3%, 90-day: 5.0%) and cardiovascular events (30-day: 8.1%, 90-day: 12.9%). The surgical related causes for readmission were pain (30-day: 13.1%, 90-day: 2.9%), wound complications (30-day: 11.3%, 90-day: 5.0% and re-herniation (30-day: 13.1%, 90-day: 2.9%). Age was the only factor with significant influence on readmission.

CONCLUSION

The incidence of medical conditions causing unplanned 30-day readmissions following surgery for lumbar degenerative conditions, is significantly higher compared to readmissions related specifically to the surgical procedure. Examples of medical treatment included antibiotics, analgesics, laxatives, anticoagulants and beta blockers. The difference is even more pronounced for the 90-day readmissions. The predominant medical causes were systemic infections, neurological and cardiovascular events. Predominant causes related to the surgery were pain, wound complications and re-herniations. Readmissions may be reduced by optimizing the medical treatment and the pain management before discharge of the patient.

Clinical Outcomes and Cost Differences Between Patients Undergoing Primary Anterior Cervical Discectomy and Fusion Procedures with Private or Medicare Insurance: A Propensity Score-Matched Study

OBJECTIVE

We assessed whether the insurance type reflects a patient's quality of care after an anterior discectomy and fusion (ACDF) procedure by comparing differences in the postoperative complications, readmission rates, reoperation rates, lengths of hospital stay, and cost of treatment between patients with Medicare versus private insurance.

METHODS

Propensity score matching was used to match patient cohorts insured by Medicare and private insurance in the MarketScan Commercial Claims and Encounters Database (2007-2016). Age, sex, year of operation, geographic region, comorbidities, and operative factors were used to match cohorts of patients who had undergone an ACDF procedure.

RESULTS

A total of 110,911 patients met the inclusion criteria. Of these patients, 97,543 patients (87.9%) were privately insured and 13,368 patients (12.1%) were insured by Medicare. The propensity score matching algorithm matched 7026 privately insured patients to 7026 Medicare patients. After matching, no significant differences were found in the 90-day postoperative complication rates, lengths of stay, or reoperation rates between the Medicare and privately insured cohorts. The Medicare group had had lower postoperative readmission rates for all time points: 30 days (1.8% vs. 4.6%; P < 0.001), 60 days (2.5% vs. 6.3%; P < 0.001), and 90 days (4.2% vs. 7.7%; P < 0.001). The median payment to physicians was significantly lower for the Medicare group ($3885 vs. $5601; P < 0.001).

CONCLUSIONS

In the present study, propensity score matched patients covered by Medicare and private insurance who had undergone an ACDF procedure had had similar treatment outcomes.

Thirty-day unplanned reoperations of thoracic spine surgery: 10 years of data from a single center with 3,242 patients

BACKGROUND CONTEXT

Unplanned reoperation is a useful quality indicator for spine surgery. However, the rates of a 30-day unplanned reoperation in patients undergoing thoracic spinal surgery are not well established.

PURPOSE

To assess the rates, reasons, and risk factors of 30-day unplanned reoperations for thoracic spine surgeries in a single center study.

STUDY DESIGN

A retrospective observational study.

PATIENT SAMPLE

3,242 patients who underwent thoracic spinal surgery at our institution in the past decade were included.

OUTCOME MEASURES

The incidence, chief reasons, and risk factors for unplanned reoperations within 30 days after thoracic spinal surgery.

METHODS

We retrospectively analyzed the data of all patients who underwent thoracic spinal surgery between January 2012 and December 2021. Statistical methods, including univariate and multivariate analyses, were performed to assess the incidence, reasons, and risk factors for thoracic degenerative diseases, spinal tumors, kyphosis deformity, and spinal trauma.

RESULTS

Of the 3,242 patients who underwent thoracic spinal surgery, 107 (3.30%) required unplanned reoperations within 30 days due to epidural hematoma (1.17%), wound complications (0.80%), implant complications (0.43%), inadequate decompression (0.25%), and other causes (0.65%). Patients with degenerative disease (3.88%), spinal tumor (2.98%), and kyphosis deformity (3.33%) had significantly higher incidences of reoperation than those with spinal trauma (1.47%). Unplanned reoperations were classified as hyperacute (30.84%), acute (31.76%), and subacute (37.38%). After univariate analysis, several factors were associated with unplanned reoperation in the 4 cohorts of thoracic spine diseases (p<.05). Multivariate logistic regression analysis revealed that upper thoracic spine surgery (p=.001), concomitant dekyphosis (p=.027), and longer activated partial thromboplastin time (p=.025) were risk factors of unplanned reoperation for thoracic degenerative disease. Whereas American Society of Anesthesiologists (ASA) grade III (p=.015), combined approach (p=.016), and operation time longer than 420 min (p=.042) for spinal tumor, and similar ankylosing spondylitis (p=.023) and operation time longer than 340 min (p=.041) were risk factors of unplanned reoperation for kyphosis deformity.

CONCLUSIONS

The unplanned reoperation rate for thoracic spine surgery was 3.30%, with epidural hematoma and wound complications being the most common reasons. However, upper thoracic spine surgery, concomitant dekyphosis, underlying coagulation disorder, longer operation time, higher ASA grade, and comorbidities of ankylosing spondylitis led to an increased risk of unplanned reoperation within 30 days of thoracic spine surgery.

Can Currently Suggested Quality Indicators Be Transferred to Meningioma Surgery?-A Single-Center Pilot Study

BACKGROUND

 Risk stratification based on standardized quality measures has become crucial in neurosurgery. Contemporary quality indicators have often been developed for a wide range of neurosurgical procedures collectively. The accuracy of tumor-inherent characteristics of patients diagnosed with meningioma remains questionable. The objective of this study was the analysis of currently applied quality indicators in meningioma surgery and the identification of potential new measures.

METHODS

 Data of 133 patients who were operated on due to intracranial meningiomas were subjected to a retrospective analysis. The primary outcomes of interest were classical quality indicators such as the 30-day readmission, 30-day reoperation, 30-day mortality, 30-day nosocomial infection, and the 30-day surgical site infection rate. Uni- and multivariate analyses were performed. The occurrence of a new postoperative neurologic deficit was analyzed as a potential new quality indicator.

RESULTS

 The overall unplanned readmission rate was 3.8%; 13 patients were reoperated within 30 days (9.8%). The 30-day nosocomial infection and surgical site infection rates were 6.8 and 1.5%, respectively. A postoperative new neurologic deficit or neurologic deterioration as a currently assessed quality feature was observed in 12 patients (9.2%). The edema volume on preoperative scans proved to have a significant impact on the occurrence of a new postoperative neurologic deficit (p = 0.023).

CONCLUSIONS

 Classical quality indicators in neurosurgery have proved to correlate with considerable deterioration of the patient's health in meningioma surgery and thus should be taken into consideration for application in meningioma patients. The occurrence of a new postoperative neurologic deficit is common and procedure specific. Thus, this should be elucidated for application as a complementary quality indicator in meningioma surgery.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors

PURPOSE

To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

PATIENTS AND METHODS

A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses.

RESULTS

The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation.

CONCLUSION

This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Incidences, causes and risk factors of unplanned reoperations within 30 days of spine surgery: a single-center study based on 35,246 patients

BACKGROUND CONTEXT

Unplanned reoperation, a quality indicator in spine surgery, has not been sufficiently investigated in a large-scale, single-center study.

PURPOSE

To assess the incidences, causes, and risk factors of unplanned reoperations within 30 days of spine surgeries in a single-center study.

STUDY DESIGN

Retrospective observational study.

PATIENT SAMPLE

A cohort of 35,246 patients who underwent spinal surgery in our hospital were included.

OUTCOME MEASURES

The rates, chief reasons, and risk factors for unplanned reoperations within 30 days of spine surgery.

METHODS

We retrospectively analyzed the data for patients who underwent spine surgeries for degenerative spinal disorders, tumor, or deformity and had subsequent unplanned operations within 30 days at a single tertiary academic hospital from January 2016 to July 2021. Univariate and multivariate analyses were performed to assess the incidences, causes, and risk factors.

RESULTS

Out of 35,246 spinal surgery patients, 297 (0.84%) required unplanned reoperations within 30 days of spine surgery. Patients with a thoracic degenerative disease (3.23%), spinal tumor (1.63%), and spinal deformity (1.50%) had significantly higher rates of reoperation than those with atlantoaxial (0.61%), cervical (0.65%), and lumbar (0.82%) degenerative disease. The common causes for reoperation included epidural hematoma (0.403%), wound infections (0.148%), neurological deficit (0.108%), and pedicle screw malposition (0.077%). Unplanned reoperations were classified as hyperacute (45.45%), acute (30.98%), subacute (15.82%), or chronic (7.74%). Univariate analysis indicated that 20 clinical factors were associated with unplanned reoperation (p<.05). Multivariate Poisson regression analysis revealed that anemia (p<.001), osteoporosis (p=.048), ankylosing spondylitis (p=.008), preoperative foot drop (p=.011), deep venous thrombosis (p<.001), and previous surgical history (p<.001) were independent risk factors for unplanned spinal reoperation.

CONCLUSIONS

The incidence of unplanned spinal reoperations was 0.84%. The chief common causes were epidural hematoma, wound infections, neurological deficit, and pedicle screw malposition. Anemia, osteoporosis, ankylosing spondylitis, preoperative foot drop, deep venous thrombosis, and previous surgical history led to an increased risk of unplanned reoperation within 30 days of spine surgery.

Risk Factors for Infection and Revision Surgery following Patellar Tendon and Quadriceps Tendon Repairs: An Analysis of 3,442 Patients

Disruption of the extensor mechanism is debilitating with surgical repair being the accepted treatment. The incidence of infection and reoperation after extensor mechanism repair are not well reported in the literature. Thus, the objective of the current study was to (1) determine the incidence of surgical site infection and reoperation within 1 year of primary extensor mechanism repair and (2) identify independent risk factors for infection and reoperation following patellar and quadriceps tendon repair. A retrospective review of the 100% Medicare Standard Analytic files from 2005 to 2014 was performed to identify patients undergoing isolated patellar tendon repair and quadriceps tendon repair. Diagnosis of infection within 1 year of operative intervention and revision repair were assessed. Extensor mechanism injuries in the setting of total knee arthroplasty and polytrauma were excluded. Multivariate logistic regression analysis was performed to evaluate risk factors for postoperative infection and reoperation within 1 year. Infection occurred in 6.3% of patients undergoing patellar tendon repair and 2.6% of patients undergoing quadriceps tendon repair. Diabetes mellitus (odds ratio [OR] = 1.89, p = 0.005) was found to be an independent risk factor for infection following patellar tendon repair. Reoperation within 1 year occurred in 1.3 and 3.9% following patellar tendon and quadriceps tendon repair, respectively. Age less than 65 years (OR = 2.77, p = 0.024) and obesity (OR = 3.66, p = 0.046) were significant risk factors for reoperation after patellar tendon repair. Hypertension (OR = 2.13, p = 0.034), hypothyroidism (OR = 2.01, p = 0.010), and depression (OR = 2.41, p = 0.005) were significant risk factors for reoperation after quadriceps tendon repair. Diabetes mellitus was identified as a risk factor for infection after patellar tendon repair. Age less than 65 years, peripheral vascular disease, and congestive heart failure were risk factors for infection after quadriceps tendon repair. The current findings can be utilized to counsel patients regarding preoperative risk factors for postoperative complications prior to surgical intervention for extensor mechanism injuries.

Association of Diabetes Mellitus With Postoperative Complications and Mortality After Non-Cardiac Surgery: A Meta-Analysis and Systematic Review

BACKGROUND

Although a variety of data showing that diabetes mellitus (DM) (Type 1 or Type 2) is associated with postoperative complication, there is still a lack of detailed studies that go through the specific diabetic subgroups. The goal of this meta-analysis is to assess the relationship between DM and various complications after non-cardiac surgery.

METHODS

We searched articles published in three mainstream electronic databases (PubMed, EMBASE, Web of science) before November, 2020. A random effects model was conducted since heterogeneity always exist when comparing results between different types of surgery.

RESULTS

This paper included 125 studies with a total sample size of 3,208,776 participants. DM was a risk factor for any postoperative complication (Odds ratio (OR)=1.653 [1.487, 1.839]). The risk of insulin-dependent DM (OR=1.895 [1.331, 2.698]) was higher than that of non-insulin-dependent DM (OR=1.554 [1.061, 2.277]) for any postoperative complication. DM had a higher risk of infections (OR=1.537 [1.322, 1.787]), wound healing disorders (OR=2.010 [1.326, 3.046]), hematoma (OR=1.369 [1.120, 1.673]), renal insufficiency (OR=1.987 [1.311, 3.013]), myocardial infarction (OR=1.372 [0.574, 3.278]). Meanwhile, DM was a risk factor for postoperative reoperation (OR=1.568 [1.124, 2.188]), readmission (OR=1.404 [1.274, 1.548]) and death (OR=1.606 [1.178, 2.191]).

CONCLUSIONS

DM is a risk factor for any postoperative complications, hospitalization and death after non-cardiac surgery. These findings underscore the importance of preoperative risk factor assessment of DM for the safe outcome of surgical patients.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Surgical Risk Assessment

BACKGROUND

Patient factors (increased body mass index [BMI], smoking, and diabetes) may impact outcomes after spine surgery. There is a lack of consensus regarding which factors should be screened for and potentially modified preoperatively to optimize outcome.

OBJECTIVE

The purpose of this evidence-based clinical practice guideline is to determine if preoperative patient factors of diabetes, smoking, and increased BMI impact surgical outcomes.

METHODS

A systematic review of the literature for studies relevant to spine surgery was performed using the National Library of Medicine PubMed database and the Cochrane Library. Clinical studies evaluating the impact of diabetes or increased BMI with reoperation and/or surgical site infection (SSI) were selected for review. In addition, the impact of preoperative smoking on patients undergoing spinal fusion was reviewed.

RESULTS

A total of 699 articles met inclusion criteria and 64 were included in the systematic review. In patients with diabetes, a preoperative hemoglobin A1c (HbA1c) >7.5 mg/dL is associated with an increased risk of reoperation or infection after spine surgery. The review noted conflicting studies regarding the relationship between increased BMI and SSI or reoperation. Preoperative smoking is associated with increased risk of reoperation (Grade B). There is insufficient evidence that cessation of smoking before spine surgery decreases the risk of reoperation.

CONCLUSION

This evidence-based guideline provides a Grade B recommendation that diabetic individuals undergoing spine surgery should have a preoperative HbA1c test before surgery and should be counseled regarding the increased risk of reoperation or infection if the level is >7.5 mg/dL. There is conflicting evidence that BMI correlates with greater SSI rate or reoperation rate (Grade I). Smoking is associated with increased risk of reoperation (Grade B) in patients undergoing spinal fusion.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/2-preoperative-surgical-risk-assessement.

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).

Influence of Osteoporosis Following Spine Surgery on Reoperation, Readmission, and Economic Costs: An 8-Year Nationwide Population-Based Study in Korea

OBJECTIVE

To evaluate the relationship between prevalence of osteoporosis and risk factors, medical costs, reoperation, and readmission in patients after spine surgery.

METHODS

Patients >50 years old with thoracic or lumbar spine diseases who underwent spine surgery between 2005 and 2008 were selected from the Korean National Health Insurance Service databases for analysis. There were 147,676 patients selected, who were divided into 2 groups (osteoporosis and non-osteoporosis) and followed for 8 years. Multiple logistic regressions were performed to examine the effect of osteoporosis following spine surgery.

RESULTS

Patients with osteoporosis showed significant increases in readmission rates (odds ratio = 1.26, P < 0.001). Osteoporosis was found to be significantly associated with longer hospital stays and increased medical costs regardless of the cause of spine disease. For readmission, there was a 62-day difference in hospitalization time and U.S. dollars $2040 difference in medical costs between the osteoporosis group and non-osteoporosis group. Total medical costs of the osteoporosis group were about U.S. dollars $310 million more than total medical costs of the non-osteoporosis group. Osteoporosis increased the risk of reoperation in fusion surgery, particularly in the first 3 months postoperatively (odds ratio = 1.34, P < 0.001).

CONCLUSIONS

Osteoporosis was significantly associated with higher readmission rates, longer hospitalization, and greater medical costs during the 8-year follow-up. It also increased the risk of reoperation in fusion surgery. Proper management of osteoporosis is essential before spine surgery, particularly fusion surgery, to help reduce patients' socioeconomic burden and produce more satisfactory surgical outcomes.

Economic analysis of 90-day return to the emergency room and readmission after elective lumbar spine surgery: a single-center analysis of 5444 patients

OBJECTIVE

In the future, payers may not cover unplanned 90-day emergency room (ER) visits or readmissions after elective lumbar spine surgery. Prior studies using large administrative databases lack granularity and/or use a proxy for actual cost. The purpose of this study was to identify risk factors and subsequent costs associated with 90-day ER visits and readmissions after elective lumbar spine surgery.

METHODS

A prospective, multisurgeon, single-center electronic medical record was queried for elective lumbar spine fusion surgeries from 2013 to 2017. Predictive models were created for 90-day ER visits and readmissions.

RESULTS

Of 5444 patients, 729 (13%) returned to the ER, most often for pain (n = 213, 29%). Predictors of an ER visit were prior ER visit (OR 2.5), underserved zip code (OR 1.4), and number of chronic medical conditions (OR 1.4). In total, 421 (8%) patients were readmitted, most frequently for wound infection (n = 123, 2%), exacerbation of chronic obstructive pulmonary disease (n = 24, 0.4%), and sepsis (n = 23, 0.4%). Predictors for readmission were prior ER visit (OR 1.96), multiple chronic conditions (OR 1.69), obesity (nonobese, OR 0.49), race (African American, OR 1.43), admission status (ER admission, OR 2.29), and elevated hemoglobin A1c (OR 1.80). The mean direct hospital cost for an ER visit was $1971, with 75% of visits costing less than $1890, and the average readmission cost was $7347, with 75% of readmissions costing less than $8820. Over the 5-year study period, the cost to the institution for 90-day return ER visits was $5.1 million.

CONCLUSIONS

Risk factors for 90-day ER visit and readmission after elective lumbar spine surgery include medical comorbidities and socioeconomic factors. Proper patient counseling, appropriate postoperative pain management, and optimization of modifiable risk factors prior to surgery are areas to focus future efforts to lower 90-day ER visits and readmissions and reduce healthcare costs.

Ninety-Day Readmission in Elective Revision Lumbar Fusion Surgery in the Inpatient Setting

STUDY DESIGN

Retrospective review.

OBJECTIVES

(1) Identify the 90-day rate of readmission following revision lumbar fusion, (2) identify independent risk factors associated with increased rates of readmission within 90 days, (3) and identify the hospital costs associated with revision lumbar fusion and subsequent readmission within 90 days.

METHODS

Utilizing 2014 data from the Nationwide Readmissions Database, patients undergoing elective revision lumbar fusion were identified. With this sample, multivariate logistic regression was utilized to identify independent predictors of readmission within 90 days. An analysis of total hospital costs was also conducted.

RESULTS

In 2014, an estimated 14 378 patients underwent elective revision lumbar fusion. The readmission rate at 90 days was 3.1% (n = 446). Diabetes with chronic complications was the only comorbidity found to carry significantly increased odds of readmission. Surgical complications such as deep venous thrombosis, surgical wound disruption, hematoma, and pneumonia (experienced during the index admission) were also independent predictors of readmission. Anterior approaches were associated with increased odds of readmission. The most common related diagnoses on readmission were hardware issues, postoperative infection, and disc herniation. Readmissions were associated with an average of $96 152 in increased hospital costs per patient compared with those not readmitted.

CONCLUSION

Relevant patient comorbidities and surgical complications were associated with increased readmission within 90 days. Readmission within 90 days was associated with significant increases in hospital costs.

Effect of change in preoperative depression/anxiety on patient outcomes following lumbar spine surgery

OBJECTIVE

The purpose of this study was to investigate the association between positive change in depression or anxiety within three months post-operation and clinically meaningful changes in long-term clinical outcomes after lumbar spine surgery.

METHODS

This study included adults with preoperative diagnosis of depression or anxiety who underwent lumbar spine surgery in the Quality Outcomes Database (QOD) from 2012 to 2018 with either a 12- or 24-month follow-up. Positive change in depression and anxiety was assessed three months after surgery. Clinical outcomes measured included Numeric Rating Scale (NRS) score for back pain (BP) and leg pain (LP), Oswestry Disability Index score (ODI) for disability, EuroQol Visual Analog Scale score (EQ-VAS) for health-related quality of life (HRQOL), and North American Spine Surgery (NASS) index score for patient satiaction measured at 12- and 24 months after surgery.

RESULTS

Of the 9,656 and 1,393 patients who were included in the 12- and 24-month cohort, respectively, 7,277 patients (75.4 %) and 1,089 (78.2 %) experienced a positive change in depression or anxiety within three months after surgery. At both 12- and 24-month follow-up, patients who had positive change in depression or anxiety were more likely to achieve minimal clinically important changes in NRS-BP/LP, ODI, EQ-VAS, and NASS (all p < 0.01) compared to those who did not experience improvement in depression or anxiety.

CONCLUSION

Depression and anxiety are important comorbidities to consider in patients undergoing lumbar spine surgery. Positive change in depression and anxiety are associated with improvements in pain, disability, satisfaction, and overall functioning.

Risk Factors for 90-day Readmissions With Fluid and Electrolyte Disorders Following Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study of the 2012 to 2014 Healthcare Cost and Utilization Project Nationwide Readmissions Database.

OBJECTIVE

To identify risk factors for 30- and 90-day readmission due to fluid and electrolyte disorders following posterior lumbar fusion.

SUMMARY OF BACKGROUND DATA

Thirty- and 90-day readmission rates are important quality and outcome measures for hospitals and physicians. These measures have been tied to financial penalties for abnormally high rates of readmission. Furthermore, complex and high cost surgeries have been increasingly reimbursed in the form of bundled disease resource group payments, where any treatment within 90-day postdischarge is covered within the original bundled payment scheme.

METHODS

A total of 65,121 patients in the Healthcare Cost and Utilization Project Nationwide Readmissions Database met our inclusion criteria, of which 1128 patients (1.7%) were readmitted within 30 days, and 1669 patients (2.6%) were readmitted within 90 days due to fluid and electrolyte abnormalities. A bivariate analysis was performed to compare baseline characteristics between patients readmitted with fluid and electrolyte disorders and the remainder of the cohort. A multivariate regression analysis was then performed to identify independent risk factors for readmission due to fluid and electrolyte disorders at 30 and 90 days.

RESULTS

The strongest independent predictors of 30-day readmissions were age ≥80 years, age 65 to 79 years, age 55 to 64 years, liver disease, and drug use disorder. The five strongest predictors of 90-day readmissions were age ≥80 years, age 65 to 79 years, age 55 to 64 years, liver disease, and fluid and electrolyte disorders.

CONCLUSION

Patients with baseline liver disease, previously diagnosed fluid and electrolyte disorders, age older than 55 years, or drug use disorders are at higher risk for readmissions with fluid and electrolyte disorders following posterior lumbar fusion. Close monitoring of fluid and electrolyte balance in the perioperative period is essential to decrease complications and reduce unplanned readmissions.

LEVEL OF EVIDENCE

3.

Disparities in Outcomes by Insurance Payer Groups for Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective, observational study of clinical outcomes at a single institution.

OBJECTIVE

To compare postoperative complication and readmission rates of payer groups in a cohort of patients undergoing anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Studies examining associations between primary payer and outcomes in spine surgery have been equivocal.

METHODS

Patients at Mount Sinai having undergone ACDF from 2008 to 2016 were queried and assigned to one of five insurance categories: uninsured, managed care, commercial indemnity insurance, Medicare, and Medicaid, with patients in the commercial indemnity group serving as the reference cohort. Multivariable logistic regression equations for various outcomes with the exposure of payer were created, controlling for age, sex, American Society of Anesthesiology Physical Status Classification (ASA Class), the Elixhauser Comorbidity Index, and number of segments fused. A Bonferroni correction was utilized, such that alpha = 0.0125.

RESULTS

Two thousand three hundred eighty seven patients underwent ACDF during the time period. Both Medicare (P < 0.0001) and Medicaid (P < 0.0001) patients had higher comorbidity burdens than commercial patients when examining ASA Class. Managed care (2.86 vs. 2.72, P = 0.0009) and Medicare patients (2.99 vs. 2.72, P < 0.0001) had more segments fused on average than commercial patients. Medicaid patients had higher rates of prolonged extubation (odds ratio [OR]: 4.99; 95% confidence interval [CI]: 1.13-22.0; P = 0.007), and Medicare patients had higher rates of prolonged length of stay (LOS) (OR: 2.44, 95% CI: 1.13-5.27%, P = 0.004) than the commercial patients. Medicaid patients had higher rates of 30- (OR: 4.12; 95% CI: 1.43-11.93; P = 0.0009) and 90-day (OR: 3.28; 95% CI: 1.34-8.03; P = 0.0009) Emergency Department (ED) visits than the commercial patients, and managed care patients had higher rates of 30-day readmission (OR: 3.41; 95% CI: 1.00-11.57; P = 0.0123).

CONCLUSION

Medicare and Medicaid patients had higher rates of prolonged LOS and postoperative ED visits, respectively, compared with commercial patients.

LEVEL OF EVIDENCE

3.

Risk Factors Associated With 90-Day Readmissions After Degenerative Lumbar Fusion: An Examination of the Michigan Spine Surgery Improvement Collaborative (MSSIC) Registry

BACKGROUND

Most studies have evaluated 30-d readmissions after lumbar fusion surgery. Evaluation of the 90-d period, however, allows a more comprehensive assessment of factors associated with readmission.

OBJECTIVE

To assess the reasons and risk factors for 90-d readmissions after lumbar fusion surgery.

METHODS

The Michigan Spine Surgery Improvement Collaborative (MSSIC) registry is a prospective, multicenter, and spine-specific database of patients surgically treated for degenerative disease. MSSIC data were retrospectively analyzed for causes of readmission, and independent risk factors impacting readmission were found by multivariate logistic regression.

RESULTS

Of 10 204 patients who underwent lumbar fusion, 915 (9.0%) were readmitted within 90 d, most commonly for pain (17%), surgical site infection (16%), and radicular symptoms (10%). Risk factors associated with increased likelihood of readmission were other race (odds ratio [OR] 1.81, confidence interval [CI] 1.22-2.69), coronary artery disease (OR 1.57, CI 1.25-1.96), ≥4 fused levels (OR 1.41, CI 1.06-1.88), diabetes (OR 1.34, CI 1.10-1.63), and surgery length (OR 1.09, CI 1.03-1.16). Factors associated with decreased risk were discharge to home (OR 0.63, CI 0.51-0.78), private insurance (OR 0.79, CI 0.65-0.97), ambulation same day of surgery (OR 0.81, CI 0.67-0.97), and spondylolisthesis diagnosis (OR 0.82, CI 0.68-0.97). Of those readmitted, 385 (42.1%) patients underwent another surgery.

CONCLUSION

Ninety-day readmission occurred in 9.0% of patients, mainly for pain, wound infection, and radicular symptoms. Increased focus on postoperative pain may decrease readmissions. Among factors impacting the likelihood of 90-d readmission, early postoperative ambulation may be most easily modifiable. Optimization of preexisting medical conditions could also potentially decrease readmission risk.

Trends in Ambulatory Laminectomy in the USA and Key Factors Associated with Successful Same-Day Discharge: A Retrospective Cohort Study

BACKGROUND

Laminectomy is commonly used in the treatment of lumbar spine pathology. Laminectomies are increasingly being performed in outpatient settings, but patient safety concerns remain.

QUESTIONS/PURPOSES

We aimed to describe trends in outpatient lumbar laminectomy between 2008 and 2016 and to identify factors associated with successful same-day discharge.

METHODS

We identified patients who underwent single-level lumbar laminectomy between 2008 and 2016 in the American College of Surgeons' National Surgical Quality Improvement Program database and divided them into two groups according to their admission status, either inpatient or outpatient. Inpatient and outpatient groups were further divided according to actual length of stay (LOS): did not remain in the hospital overnight (LOS = 0) or stayed in the hospital overnight or longer (LOS ≥ 1). We then analyzed patient characteristics and complications for significance and to identify factors associated with successful same-day discharge.

RESULTS

We identified 85,769 patients, 41,149 classified as outpatient status and 44,620 as inpatient status. Between 2008 and 2016, the proportion of procedures performed on an outpatient basis increased from 24.1 to 56.74%. Overall, 27.3% of all patients were discharged on the day of surgery, representing 52.8% of outpatients and 3.8% of inpatients. Older age and longer duration of surgery predicted that patients were less likely to have same-day discharge. Patients with a primary diagnosis other than intervertebral disk disorder, Hispanic ethnic background, or an American Society of Anesthesiologists physical status classification of III were less likely to achieve same-day discharge. Patients under the care of orthopedic surgeons (as opposed to neurosurgeons) were more likely to be discharged on the day of surgery. We also found an association between sex and day of discharge, with female patients being less likely to be discharged on the day of surgery.

CONCLUSIONS

Laminectomy is increasingly being performed in the outpatient setting. Younger, healthier non-Hispanic male patients undergoing uncomplicated surgery have a higher likelihood of successful same-day discharge.

Ambulation on Postoperative Day #0 Is Associated With Decreased Morbidity and Adverse Events After Elective Lumbar Spine Surgery: Analysis From the Michigan Spine Surgery Improvement Collaborative (MSSIC)

BACKGROUND

While consistently recommended, the significance of early ambulation after surgery has not been definitively studied.

OBJECTIVE

To identify the relationship between ambulation on the day of surgery (postoperative day (POD)#0) and 90-d adverse events after lumbar surgery.

METHODS

The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a prospective multicenter registry of spine surgery patients. As part of routine postoperative care, patients either ambulated on POD#0 or did not. The 90-d adverse events of length of stay (LOS), urinary retention (UR), urinary tract infection (UTI), ileus, readmission, surgical site infection (SSI), pulmonary embolism/deep vein thrombosis (PE/DVT), and disposition to a rehab facility were measured.

RESULTS

A total of 23 295 lumbar surgery patients were analyzed. POD#0 ambulation was associated with decreased LOS (relative LOS 0.83, P &lt; .001), rehab discharge (odds ratio [OR] 0.52, P &lt; .001), 30-d (OR 0.85, P = .044) and 90-d (OR 0.86, P = .014) readmission, UR (OR 0.73, P = 10), UTI (OR 73, P = .001), and ileus (OR 0.52, P &lt; .001) for all patients. Significant improvements in LOS, rehab discharge, readmission, UR, UTI, and ileus were observed in subset analysis of single-level decompressions (4698 pts), multilevel decompressions (4079 pts), single-level fusions (4846 pts), and multilevel fusions (4413 pts). No change in rate of SSI or DVT/PE was observed for patients who ambulated POD#0.

CONCLUSION

POD#0 ambulation is associated with a significantly decreased risk for several key adverse events after lumbar spine surgery. Decreasing the incidence of these outcomes would be associated with significant cost savings. As ambulation POD#0 is a modifiable factor in any patient's postoperative care following most spine surgery, it should be encouraged and incorporated into spine-related, enhanced-recovery-after-surgery programs.

Use of Patient Health Questionnaire-2 scoring to predict patient satisfaction and return to work up to 1 year after lumbar fusion: a 2-year analysis from the Michigan Spine Surgery Improvement Collaborative

OBJECTIVE

The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a prospective, longitudinal, multicenter, quality-improvement collaborative. Using MSSIC, the authors sought to identify the relationship between a positive Patient Health Questionnaire-2 (PHQ-2) screening, which is predictive of depression, and patient satisfaction, return to work, and achieving Oswestry Disability Index (ODI) minimal clinically important difference (MCID) scores up to 2 years after lumbar fusion.

METHODS

Data from a total of 8585 lumbar fusion patients were analyzed. Patient satisfaction was measured by the North American Spine Society patient satisfaction index. A positive PHQ-2 score is one that is ≥ 3, which has an 82.9% sensitivity and 90.0% specificity in detecting major depressive disorder. Generalized estimating equation models were constructed; variables tested include age, sex, race, past medical history, severity of surgery, and preoperative opioid usage.

RESULTS

Multivariate analysis was performed. Patients with a positive PHQ-2 score (i.e., ≥ 3) were less likely to be satisfied after lumbar fusion at 90 days (relative risk [RR] 0.93, p < 0.001), 1 year (RR 0.92, p = 0.001), and 2 years (RR 0.92, p = 0.028). A positive PHQ-2 score was also associated with decreased likelihood of returning to work at 90 days (RR 0.76, p < 0.001), 1 year (RR 0.85, p = 0.001), and 2 years (RR 0.82, p = 0.031). A positive PHQ-2 score was predictive of failure to achieve an ODI MCID at 90 days (RR 1.07, p = 0.005) but not at 1 year or 2 years after lumbar fusion.

CONCLUSIONS

A multivariate analysis based on information from a large, multicenter, prospective database on lumbar fusion patients was performed. The authors found that a positive score (≥ 3) on the PHQ-2, which is a simple and accurate screening tool for depression, predicts an inability to return to work and worse satisfaction up to 2 years after lumbar fusion. Depression is a treatable condition, and so in the same way that patients are medically optimized before surgery to decrease postoperative morbidity, perhaps patients should have preoperative psychiatric optimization to improve postoperative functional outcomes.

90-day Readmission in Elective Primary Lumbar Spine Surgery in the Inpatient Setting: A Nationwide Readmissions Database Sample Analysis

STUDY DESIGN

Secondary analysis of a large administrative database.

OBJECTIVE

The objectives of this study are to: 1) identify the incidence and cause of 90-day readmissions following primary elective lumbar spine surgery, 2) offer insight into potential risk factors that contribute to these readmissions, and 3) quantify the cost associated with these readmissions.

SUMMARY OF BACKGROUND DATA

As bundled-payment models for the reimbursement of surgical services become more popular in spine, the focus is shifting toward long-term patient outcomes in the context of 90-day episodes of care. With limited data available on national 90-day readmission statistics available, we hope to provide evidence that will aid in the development of more cost-effective perioperative care models.

METHODS

Using ICD-9 coding, we identified all patients 18 years of age and older in the 2014 Nationwide Readmissions Database (NRD) who underwent an elective, inpatient, primary lumbar spine surgery. Using multivariate logistic regression, we identified independent predictors of 90-day readmission while controlling for a multitude of confounding variables and completed a comparative cost analysis.

RESULTS

We identified 169,788 patients who underwent a primary lumbar spine procedure. In total 4268 (2.5%) were readmitted within 90 days. There was no difference in comorbidity burden between cohorts (readmitted vs. not readmitted) as quantified by the Elixhauser Comorbidity index. Independent predictors of increased odds of 90-day readmission were: anemia, uncomplicated diabetes and diabetes with chronic complications, surgical wound disruption and acute myocardial infarction at the time of the index admission, self-pay status, and an anterior surgical approach. Implant complications were identified as the primary related cause of readmission. These readmissions were associated with a significant cost increase.

CONCLUSION

There are clearly identifiable risk factors that increase the odds of hospital readmission within 90 days of primary lumbar spine surgery. An overall 90-day readmission rate of 2.5%, while relatively low, carries significantly increased cost to both the patient and hospital.

LEVEL OF EVIDENCE

3.

Risk factors for 90-day reoperation and readmission after lumbar surgery for lumbar spinal stenosis

OBJECTIVES

The objective of this study was to evaluate the incidence and risk factors for 90-day readmission and reoperation after elective surgery for lumbar spinal stenosis (LSS).

METHODS

The authors performed a retrospective consecutive cohort analysis of patients undergoing posterior lumbar decompression with or without fusion for LSS with claudication from January 2014 through December 2015.

RESULTS

Data were collected on 1592 consecutive patients. The mean age at surgery was 67.4 ± 10.1 years and 45% of patients were female. The 90-day reoperation rate was 4.7%, and 69.3% of the reoperations occurred within the first 30 days. The 90-day readmission rate was 7.2%. Multivariable analysis showed that postoperative development of a surgical site infection (SSI; odds ratio [OR] 14.09, 95% confidence interval [CI] 7.86–25.18), acute kidney injury (AKI; OR 6.76, 95% CI 2.39–19.57), and urinary tract infection (UTI; OR 3.96, 95% CI 2.43–6.37), as well as a history of congestive heart failure (CHF; OR 3.03, 95% CI 1.69–5.28), were significant risk factors for readmission within 90 days. Male sex (OR 0.60, 95% CI 0.38–0.92) was associated with decreased odds for readmission. With regards to reoperation, development of SSI (OR 25.06, 95% CI 13.54–46.51), sepsis (OR 7.63, 95% CI 1.52–40.59), UTI (OR 2.54, 95% CI 1.31–4.76), and increased length of stay (LOS; OR 1.25, 95% CI 1.17–1.33) were found to be significant risk factors. A subsequent analysis found that morbid obesity (OR 6.99), history of coronary artery disease (OR 2.263), increased duration of surgery (OR 1.004), and LOS (OR 1.07) were significant risk factors for developing an SSI.

CONCLUSIONS

Overall, this study found rates of 4.7% and 7.2% for reoperation and readmission, respectively, within 90 days: 30.7% of the reoperations and 44.7% of the readmissions occurred beyond the first 30 days. A diagnosis of SSI, AKI, UTI, and history of CHF were significant factors for readmission, while male sex was associated with decreased odds for readmission. A diagnosis of SSI, sepsis, UTI, and increased LOS were found to be significant predictors for reoperation. Understanding 90-day complication rates is imperative because there has been increased discussion and healthcare policy extending the global postoperative window to 90 days. Current literature supports a readmission rate of 3%–9% after spine surgery. However, this literature either is limited to a 30-day window or does not stratify between different types of spine surgeries.

ABBREVIATIONS

AKI = acute kidney injury; BPH = benign prostate hyperplasia; CAD = coronary artery disease; CHF = congestive heart failure; CI = confidence interval; CMS = Centers for Medicare and Medicaid Services; COPD = chronic obstructive pulmonary disease; DM = diabetes mellitus; EBL = estimated blood loss; LOS = length of stay; LSS = lumbar spinal stenosis; OR = odds ratio; POUR = postoperative urinary retention; SSI = surgical site infection; UTI = urinary tract infection.

Surgical Risk Assessment and Prevention in Elderly Spinal Deformity Patients

Introduction:

Prevalence of adult deformity surgery in the elderly individuals continues to increase. These patients have additional considerations for the spine surgeon during surgical planning. We perform an informative review of the spinal and geriatric literature to assess preoperative and intraoperative factors that impact surgical complication occurrences in this population.

Significance:

There is a need to understand surgical risk assessment and prevention in geriatric patients who undergo thoracolumbar adult deformity surgery in order to prevent complications.

Methods:

Searches of relevant biomedical databases were conducted by a medical librarian. Databases searched included MEDLINE, Web of Science, CINAHL, IPA, Cochrane, PQ Health and Medical, SocINDEX, and WHO’s Global Health Library. Search strategies utilized Medical Subject Headings plus text words for extensive coverage of scoliosis and surgical technique concepts.

Results:

Degenerative scoliosis affects 68% of the geriatric population, and the rate of surgical interventions for this pathology continues to increase. Complications following spinal deformity surgery in this patient population range from 37% to 62%. Factors that impact outcomes include age, comorbidities, blood loss, and bone quality. Using these data, we summarize multimodal risk prevention strategies that can be easily implemented by spine surgeons.

Conclusions:

After evaluation of the latest literature on the complications associated with adult deformity surgery in geriatric patients, comprehensive perioperative management is necessary for improved outcomes. Preoperative strategies include assessing physiological age via frailty score, nutritional status, bone quality, dementia/delirium risk, and social activity support. Intraoperative strategies include methods to reduce blood loss and procedural time. Postoperatively, development of a multidisciplinary team approach that encourages early ambulation, decreases opiate use, and ensures supportive discharge planning is imperative for better outcomes for this patient population.

Adverse events and their risk factors 90 days after cervical spine surgery: analysis from the Michigan Spine Surgery Improvement Collaborative

OBJECTIVE

The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a statewide, multicenter quality improvement initiative. Using MSSIC data, the authors sought to identify 90-day adverse events and their associated risk factors (RFs) after cervical spine surgery.

METHODS

A total of 8236 cervical spine surgery cases were analyzed. Multivariable generalized estimating equation regression models were constructed to identify RFs for adverse events; variables tested included age, sex, diabetes mellitus, disc herniation, foraminal stenosis, central stenosis, American Society of Anesthesiologists Physical Classification System (ASA) class > II, myelopathy, private insurance, anterior versus posterior approach, revision procedures, number of surgical levels, length of procedure, blood loss, preoperative ambulation, ambulation day of surgery, length of hospital stay, and discharge disposition.

RESULTS

Ninety days after cervical spine surgery, adverse events identified included radicular findings (11.6%), readmission (7.7%), dysphagia requiring dietary modification (feeding tube or nothing by mouth [NPO]) (6.4%), urinary retention (4.7%), urinary tract infection (2.2%), surgical site hematoma (1.1%), surgical site infection (0.9%), deep vein thrombosis (0.7%), pulmonary embolism (0.5%), neurogenic bowel/bladder (0.4%), myelopathy (0.4%), myocardial infarction (0.4%), wound dehiscence (0.2%), claudication (0.2%), and ileus (0.2%). RFs for dysphagia included anterior approach (p < 0.001), fusion procedures (p = 0.030), multiple-level surgery when considering anterior procedures only (p = 0.037), and surgery duration (p = 0.002). RFs for readmission included ASA class > II (p < 0.001), while preoperative ambulation (p = 0.001) and private insurance (p < 0.001) were protective. RFs for urinary retention included increasing age (p < 0.001) and male sex (p < 0.001), while anterior-approach surgery (p < 0.001), preoperative ambulation (p = 0.001), and ambulation day of surgery (p = 0.001) were protective. Preoperative ambulation (p = 0.010) and anterior approach (p = 0.002) were protective of radicular findings.

CONCLUSIONS

A multivariate analysis from a large, multicenter, prospective database identified the common adverse events after cervical spine surgery, along with their associated RFs. This information can lead to more informed surgeons and patients. The authors found that early mobilization after cervical spine surgery has the potential to significantly decrease adverse events.

30-Day Emergency Department Visits After Primary Lumbar Fusion: Incidence, Causes, Risk Factors, and Costs

Our objective was to describe the incidence, causes, risk factors, and costs associated with 30-day emergency department (ED) visits after primary lumbar fusion. A national insurance database was retrospectively analyzed to study patients with primary lumbar fusions performed for degenerative pathology of the spine between 2007 and Q3-2015. Risk factors for ED visits, and ED to hospital transfer were studied using multiple-variable logistic regression analysis. Our cohort included 37,559 patients with a mean age of 66.0±10.0 years. A total of 4806 (12.8%) patients had 10,281 ED visits within 30 days after surgery. Of these, 945 (19.9%) had multiple (≥3) visits, and 1466 (30.5%) were admitted to the hospital for management. Common causes for presentation in the ED were cardiorespiratory complaints (49.4%, n=2377), and back and/or leg pain (47.7%, n=2294). Risk factors for all ED visits, multiple ED visits, and hospital admission from the ED have been identified. The overall ED cost burden was nearly two-thirds as much as hospital readmissions within 30 days ($6,994,260 vs. $10,880,999). There is a sizable subset of patients that present to the ED for acute care but do not require hospitalization. Causes and risk factors for presentation in patients with multiple ED visits are somewhat different than patients requiring hospital readmission.

Analysis of Risk Factors Associated with Hospital Readmission Within 360 Days After Degenerative Lumbar Spine Surgery in Elderly Patients

OBJECTIVE

There is a paucity of studies on readmission rates in elderly patients over a period of 360 days after spinal surgery.

METHODS

We identified 1248 patients older than 70 years who underwent degenerative lumbar spinal surgery from November 2005 to April 2015. We reviewed the patients who were readmitted within 360 days and compared them by univariate and multivariate analysis with the nonreadmitted patients for each period of 0-30, 30-90, 90-180, and 180-360 days postoperatively to determine risk factors for hospital readmission.

RESULTS

A total of 1248 patients (733 female, 58.7%) were enrolled in the study. The number of readmitted patients was 37 (2.96%), 94 (7.53%), 145 (11.62%), 182 (14.58%), and 213 (17.07%) at 30, 90, 180, 270, and 360 days, respectively. Surgical site-related problems decreased gradually in the first 0-90 days and slightly increased after then. Non-surgical site-related problems gradually increased with time. Logistic multiple regression analysis showed that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low alanine aminotransferase level, high body mass index, and high platelet level were risk factors for readmission.

CONCLUSIONS

We found that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low aspartate aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. As the postoperative observational period became longer, the reasons for readmission tended to be more related to non-surgical site-related problems than to surgical-related problems.

What are the Rates, Reasons, and Risk Factors of 90-day Hospital Readmission After Lumbar Discectomy?: An Institutional Experience

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To report the rate, reasons, and risk factors for 90-day readmissions after lumbar discectomy at an academic medical center.

SUMMARY OF BACKGROUND DATA

Several studies have reported complications and readmissions after spine surgery; however, only one previous study has focused specifically on lumbar discectomy. As the patient profile and morbidity of various spine procedures is different, focus on procedure-specific complications and readmissions will be beneficial.

MATERIALS AND METHODS

Patients who underwent lumbar discectomy for unrelieved symptoms of prolapsed intervertebral disk and had at least 90 days of follow-up at an academic institution (2013-2014) were included. Retrospective review of electronic medical record was performed to record demographic and clinical profile of patients. Details of lumbar discectomy, index hospital stay, discharge disposition, hospital readmission within 90 days, reason for readmission and treatment given have been reported. Risk factors for hospital readmission were analyzed by multivariate logistic regression analysis.

RESULTS

A total of 356 patients with a mean age of 45.0±13.8 years were included. The 90-day readmission rate was 5.3% (19/360) of which two-third patients were admitted within 30 days giving a 30-day readmission rate of 3.7% (13/356). The top 2 primary reasons for readmission included back and/or leg pain, numbness, or tingling (42.9%), and persistent cerebrospinal fluid leak or seroma (25.0%). On adjusted analysis, risk factors associated with higher risk of readmission included incidental durotomy [odds ratio (OR), 26.2; 95% confidence interval (CI), 5.3-129.9] and discharge to skilled nursing facility/inpatient rehabilitation (OR, 25.2; 95% CI, 2.7-235.2). Increasing age was a negative predictor of readmission (OR, 0.95; 95% CI, 0.91-0.99).

CONCLUSIONS

Incidental durotomy, younger age, and discharge to nursing facility were associated with higher risk of 90-day hospital readmission after lumbar discectomy. As compared with extensive spine procedures, patient comorbidity burden may not be as significant in predicting readmission after this relatively less invasive procedure.

Outpatient Spine Clinic Utilization is Associated With Reduced Emergency Department Visits Following Spine Surgery

STUDY DESIGN

Review of TRICARE claims (2006-2014) data to assess Emergency Department (ED) utilization following spine surgery.

OBJECTIVE

The aim of this study was to determine utilization rates and predictors of ED utilization following spine surgical interventions.

SUMMARY OF BACKGROUND DATA

Visits to the ED following surgical intervention represent an additional stress to the healthcare system. While factors associated with readmission following spine surgery have been studied, drivers of postsurgical ED visits, including appropriate and inappropriate use, remain underinvestigated.

METHODS

TRICARE claims were queried to identify patients who had undergone one of three common spine procedures (lumbar arthrodesis, discectomy, decompression). ED utilization at 30- and 90 days was assessed as the primary outcome. Outpatient spine surgical clinic utilization was considered the primary predictor variable. Multivariable logistic regression was used to adjust for confounders.

RESULTS

Between 2006 and 2014, 48,868 patients met inclusion criteria. Fifteen percent (n = 7183) presented to the ED within 30 days postdischarge. By 90 days, 29% of patients (n = 14,388) presented to an ED. The 30- and 90-day complication rates were 6% (n = 2802) and 8% (n = 4034), respectively, and readmission rates were 5% (n = 2344) and 8% (n = 3842), respectively. Use of outpatient spine clinic services significantly reduced the likelihood of ED utilization at 30 [odds ratio (OR) 0.48; 95% confidence interval (95% CI) 0.46-0.53] and 90 days (OR 0.55; 95% CI 0.52-0.57).

CONCLUSION

Within 90 days following spine surgery, 29% of patients sought care in the ED. However, only one-third of these patients had a complication recorded, and even fewer were readmitted. This suggests a high rate of unnecessary ED utilization. Outpatient utilization of spine clinics was the only factor independently associated with a reduced likelihood of ED utilization.

LEVEL OF EVIDENCE

3.