Trends in Comorbidities and Complications Among Patients Undergoing Inpatient Spine Surgery

Impact of Supine versus Prone Positioning on Segmental Lumbar Lordosis in Patients Undergoing ALIF Followed by PSF: A Comparative Study

Background: Anterior lumbar interbody fusion (ALIF) and posterior spinal fusion (PSF) play pivotal roles in restoring lumbar lordosis in spinal surgery. There is an ongoing debate between combined single-position surgery and traditional prone-position PSF for optimizing segmental lumbar lordosis. Methods: This retrospective study analyzed 59 patients who underwent ALIF in the supine position followed by PSF in the prone position at a single institution. Cobb angles were measured preoperatively, post-ALIF, and post-PSF using X-ray imaging. One-way repeated measures ANOVA and post-hoc analyses with Bonferroni adjustment were employed to compare mean Cobb angles at different time points. Cohen's d effect sizes were calculated to assess the magnitude of changes. Sample size calculations were performed to ensure statistical power. Results: The mean segmental Cobb angle significantly increased from preoperative (32.2 ± 13.8 degrees) to post-ALIF (42.2 ± 14.3 degrees, Cohen's d: -0.71, p < 0.0001) and post-PSF (43.6 ± 14.6 degrees, Cohen's d: -0.80, p < 0.0001). There was no significant difference between Cobb angles after ALIF and after PSF (Cohen's d: -0.10, p = 0.14). The findings remained consistent when Cobb angles were analyzed separately for single-screw and double-screw ALIF constructs. Conclusions: Both supine ALIF and prone PSF significantly increased segmental lumbar lordosis compared to preoperative measurements. The negligible difference between post-ALIF and post-PSF lordosis suggests that supine ALIF followed by prone PSF can be an effective approach, providing flexibility in surgical positioning without compromising lordosis improvement.

Socioeconomic disparities in lumbar fusion rates were exacerbated during the COVID-19 pandemic

Background

The COVID-19 pandemic disrupted healthcare access and utilization throughout the US, with variable impact on patients of different socioeconomic status (SES) and race. We characterize pre-pandemic and pandemic demographic and SES trends of lumbar fusion patients in the US.

Methods

Adults undergoing first-time lumbar fusion 1/1/2004-3/31/2021 were assessed in Clinformatics® Data Mart for patient age, geographical location, gender, race, education level, net worth, and Charlson Comorbidity Index (CCI). Multivariable regression models were used to evaluate the significance of trends over time, with a focus on pandemic trends 2020-2021 versus previous trends 2004-2019.

Results

The total 217,204 patients underwent lumbar fusions, 1/1/2004-3/31/2021. The numbers and per capita rates of lumbar fusions increased 2004-2019 and decreased in 2020 (first year of COVID-19 pandemic), with large variation in geographic distribution. There was overall a significant decrease in proportion of White patients undergoing lumbar fusion over time (OR=0.997, p<.001), though they were more likely to undergo surgery during the pandemic (OR=1.016, p<.001). From 2004-2021, patients were more likely to be educated beyond high school. Additionally, patients in the highest (>$500k) and lowest (<$25k) net worth categories had significantly more fusions over time (p<.001). During the pandemic (2020-2021), patients in higher net worth groups were more likely to undergo lumbar fusions ($150k-249k & $250k-499k: p<.001) whereas patients in the lowest net worth group had decreased rate of surgeries (p<.001). Lastly, patients' CCI increased significantly from 2004 to 2021 (coefficient=0.124, p<.001), and this trend held true during the pandemic (coefficient=0.179, p<.001).

Conclusions

To the best of our knowledge, our work represents the most comprehensive and recent characterization of SES variables in lumbar fusion rates. Unsurprisingly, lumbar fusions decreased overall with the onset of the COVID-19 pandemic. Importantly, disparities in fusion patients across patient race and wealth widened during the pandemic, reversing years of progress, a lesson we can learn for future public health emergencies.

Demographic and Socioeconomic Trends in Cervical Fusion Utilization from 2004 Through 2021 and the COVID-19 Pandemic

BACKGROUND

Cervical fusion rates increased in the U.S. exponentially 1990-2014, but trends leading up to/during the COVID-19 pandemic have not been fully evaluated by patient socioeconomic status (SES). Here, we provide the most recent, comprehensive characterization of demographic and SES trends in cervical fusions, including during the pandemic.

METHODS

We collected the following variables on adults undergoing cervical fusions, 1/1/2004-3/31/2021, in Optum's Clinformatics Data Mart: age, Charlson Comorbidity Index, provider's practicing state, gender, race, education, and net worth. We performed multivariate linear and logistic regression to evaluate associations of cervical fusion rates with SES variables.

RESULTS

Cervical fusion rates increased 2004-2016, then decreased 2016-2020. Proportions of Asian, Black, and Hispanic patients undergoing cervical fusions increased (OR = 1.001,1.001,1.004, P < 0.01), with a corresponding decrease in White patients (OR = 0.996, P < 0.001) over time. There were increases in cervical fusions in higher education groups (OR = 1.006, 1.002, P < 0.001) and lowest net worth group (OR = 1.012, P < 0.001). During the pandemic, proportions of White (OR = 1.015, P < 0.01) and wealthier patients (OR ≥ 1.015, P < 0.01) undergoing cervical fusions increased.

CONCLUSIONS

We present the first documented decrease in annual cervical surgery rates in the U.S. Our data reveal a bimodal distribution for cervical fusion patients, with racial-minority, lower-net-worth, and highly-educated patients receiving increasing proportions of surgical interventions. White and wealthier patients were more likely to undergo cervical fusions during the COVID-19 pandemic, which has been reported in other areas of medicine but not yet in spine surgery. There is still considerable work needed to improve equitable access to spine care for the entire U.S.

POPULATION

Association Between Age-stratified Cohorts and Perioperative Complications and 30-day and 90-day Readmission in Patients Undergoing Single-level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To assess perioperative complication rates and readmission rates after ACDF in a patient population of advanced age.

SUMMARY OF BACKGROUND DATA

Readmission rates after ACDF are important markers of surgical quality and, with recent shifts in reimbursement schedules, they are rapidly gaining weight in the determination of surgeon and hospital reimbursement.

METHODS

Patients 18 years of age and older who underwent elective single-level ACDF were identified in the National Readmissions Database (NRD) and stratified into 4 cohorts: 18-39 ("young"), 40-64 ("middle"), 65-74 ("senior"), and 75+ ("elderly") years of age. For each cohort, the perioperative complications, frequency of those complications, and number of patients with at least 1 readmission within 30 and 90 days of discharge were analyzed. χ 2 tests were used to calculate likelihood of complications and readmissions.

RESULTS

There were 1174 "elderly" patients in 2016, 1072 in 2017, and 1010 in 2018 who underwent ACDF. Their rate of any complication was 8.95%, 11.00%, and 13.47%, respectively ( P <0.0001), with dysphagia and acute posthemorrhagic anemia being the most common across all 3 years. They experienced complications at a greater frequency than their younger counterparts (15.80%, P <0.0001; 16.98%, P <0.0001; 21.68%, P <0.0001). They also required 30-day and 90-day readmission more frequently ( P <0.0001).

CONCLUSION

It has been well-established that advanced patient age brings greater risk of perioperative complications in ACDF surgery. What remains unsettled is the characterization of this age-complication relationship within specific age cohorts and how these complications inform patient hospital course. Our study provides an updated analysis of age-specific complications and readmission rates in ACDF patients. Orthopedic surgeons may account for the rise in complication and readmission rates in this population with the corresponding reduction in length and stay and consider this relationship before discharging elderly ACDF patients.

Risk Factors for Significant Intraoperative Blood Loss during Anterior Cervical Decompression and Fusion for Degenerative Cervical Diseases

OBJECTIVES

Anterior cervical decompression and fusion (ACF) has become a widely accepted surgical treatment for degenerative cervical diseases, but occasionally, significant intraoperative blood loss (SIBL), which is defined as IBL of 500 mL or more, will occur. We aimed to investigate the independent risk factors for SIBL during ACF for degenerative cervical diseases.

METHODS

We enrolled 1150 patients who underwent ACF for degenerative cervical diseases at our hospital between 2013 and 2019. The patients were divided into two groups: the SIBL group (n = 38) and the non-SIBL group (n = 1112). Demographic, surgical and radiographic data were recorded prospectively to investigate the independent risk factors for SIBL. For counting data, the chi-square test or Fisher's exact probability test was used. Student's t-test or the Mann-Whitney rank sum test was used for comparisons between groups of measurement data. Univariate analysis and multivariate logistic regression analysis were further used to analyze the significance of potential risk factors.

RESULTS

The incidence of SIBL during ACF was 3.3% (38/1150). A multivariate analysis revealed that female sex (odds ratio [OR], 6.285; 95% confidence interval [CI], 2.707-14.595; p < 0.001), corpectomy (OR, 3.872; 95% CI, 1.616-9.275; p = 0.002), duration of operation ≥150 min (OR, 8.899; 95% CI, 4.042-19.590; p < 0.001), C3 involvement (OR, 4.116; 95% CI, 1.808-9.369; p = 0.001) and ossification of posterior longitudinal ligament (OPLL) at the surgical level (OR, 6.007; 95% CI, 2.218-16.270; p < 0.001) were independent risk factors for SIBL. Patients with SIBL had more days of first-degree/intensive nursing (p = 0.003), longer length of stay (p = 0.003) and higher hospitalization costs (p = 0.023).

CONCLUSION

Female sex, corpectomy, duration of operation, C3 involvement and OPLL at the surgical level were independent risk factors for SIBL during ACF. SIBL in ACF was associated with more days of first-degree/intensive nursing, longer length of stay and higher hospitalization costs.

Assessment of Risk Factors for Postoperative Delirium in Older Adults Who Underwent Spinal Surgery and Identifying Associated Biomarkers Using Exosomal Protein

PURPOSE

With an increase in the aging population, the number of patients with degenerative spinal diseases undergoing surgery has risen, as has the incidence of postoperative delirium. This study aimed to investigate the risk factors affecting postoperative delirium in older adults who had undergone spine surgery and to identify the associated biomarkers.

METHODS

This study is a prospective study. Data of 100 patients aged ≥ 70 years who underwent spinal surgery were analyzed. Demographic data, medical history, clinical characteristics, cognitive function, depression symptoms, functional status, frailty, and nutritional status were investigated to identify the risk factors for delirium. The Confusion Assessment Method, Delirium Rating Scale-R-98, and Nursing Delirium Scale were also used for diagnosing delirium. To discover the biomarkers, urine extracellular vesicles (EVs) were analyzed for tau, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), neurofilament light, and glial fibrillary acidic protein using digital immunoassay technology.

RESULTS

Nine patients were excluded, and data obtained from the remaining 91 were analyzed. Among them, 18 (19.8%) developed delirium. Differences were observed between participants with and without delirium in the contexts of a history of mental disorder and use of benzodiazepines (p = .005 and p = .026, respectively). Tau and UCH-L1-concentrations of urine EVs-were comparatively higher in participants with severe delirium than that in participants without delirium (p = .002 and p = .001, respectively).

CONCLUSION

These findings can assist clinicians in accurately identifying the risk factors before surgery, classifying high-risk patients, and predicting and detecting delirium in older patients. Moreover, urine EV analysis revealed that postoperative delirium following spinal surgery is most likely associated with brain damage.

Perioperative Management of Comorbidities in Spine Surgery

The number of spinal operations performed in the United States has significantly increased in recent years. Along with these rising numbers, there has been a corresponding increase in the number of patient comorbidities. The focus of this article is to review comorbidities in Spine surgery patients and outline strategies to optimize patients and avoid complications.

Trends in Single-Level Lumbar Fusions Over the Past Decade Using a National Database

OBJECTIVE

To compare rates of different fusion techniques using a nationwide database over the last decade and identify differences in complications and readmissions based on fusion technique.

METHODS

All elective, single-level lumbar fusions performed by orthopaedic surgeons from 2011 to 2020 were identified from the American College of Surgeons National Surgical Quality Improvement Program. Rates of lumbar fusion technique posterolateral decompression and fusion [PLDF], combined transforaminal lumbar interbody fusion and PLDF, anterior lumbar or lateral lumbar interbody fusion [ALIF/LLIF], and combined ALIF/LLIF and PLDF were recorded, and 30-day complications and readmissions were compared. Secondary analysis included multiple logistic regression to determine independent predictors of each outcome.

RESULTS

Inclusion criteria were met by 28,413 fusions: 8749 (30.8%) PLDFs, 11,973 (42.1%) transforaminal lumbar interbody fusions, 4769 (16.8%) ALIF/LLIFs, and 2922 (10.3%) combined ALIF/LLIF and PLDFs. The number of fusions increased over time with 1227 fusions performed in 2011 and 3958 fusions performed in 2019. Interbody fusions also increased over time with a subsequent decrease in PLDFs (39.0% in 2011, 25.2% in 2020). Patients were more likely to be discharged home over the course of the decade (85.4% in 2011, 95.0% in 2020). No difference was observed between the techniques regarding complications or readmissions. The modified 5-item frailty index was predictive of complications (odds ratio, 2.05; P = 0.001) and readmissions (odds ratio, 2.61; P < 0.001).

CONCLUSIONS

Lumbar fusions have continued to increase over the last decade with an increasing proportion of interbody fusions. Complications and readmissions appear to be driven by patient comorbidity and not fusion technique.

Development and validation of a risk-based algorithm for preoperative type and screen testing in spine surgery

BACKGROUND CONTEXT

With improvements in surgical techniques and perioperative management, transfusion rates after spine surgery have decreased over time. Given this trend, routine preoperative ABO/Rh type and antibody screen (T&S) laboratory testing may not be warranted in all patients undergoing spine surgery.

PURPOSE

The aim of the current study is to evaluate risk factors for intra/postoperative transfusion in patients undergoing a variety of spine procedures and to develop an algorithm for selectively ordering preoperative T&S testing in appropriate patients.

STUDY DESIGN/SETTING

This is a single institution, retrospective observational study of patients undergoing emergent or elective spine surgery. External validation of the algorithm was performed on a national sample of patients undergoing spine surgery from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) national database.

PATIENT SAMPLE

A total of 5,947 surgeries from January 1, 2016 to December 31, 2019 at a single institution, and 166,113 surgeries from the 2016 to 2018 ACS-NSQIP database.

OUTCOME MEASURES

The primary outcome measure was performance of intraoperative or postoperative transfusion.

METHODS

Using the institutional sample, univariate statistics (chi-square tests, fisher's exact test, 2-sided independent sample tests) were performed to compare demographics, comorbidities, and surgical details (case type, number of levels treated, etc.) between patients who did and did not require intra- or postoperative transfusion. Transfusion rates were calculated and compared across procedure types. Multivariate logistic regression was performed to identify independent predictors of transfusion and the model's accuracy was evaluated using the area under the curve (AUC) of the receiver operating characteristics (ROC) curve. A risk-based algorithm suggesting no preoperative T&S in low transfusion risk procedures, routine preoperative T&S in high-risk procedures, and further assessment in medium risk thoracolumbar fusion procedures was created. The algorithm's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated when it was applied to both the institutional and national samples. Potential cost savings from reducing T&S orders were calculated.

RESULTS

In the institutional sample, 120 patients (2.0%) required intraoperative or postoperative transfusion. The highest rates of transfusion were found in corpectomy (10.5%) and anterior/posterior cervical fusion (6.9%) procedures. In the multivariate logistic regression model, the presence of a preoperative coagulation defect or hemorrhagic condition (OR: 7.149, p<.001) and 6+ level surgery (OR: 7.511, p<.001) were the strongest predictors of transfusion. Overall, the model generated an AUC of 0.882, indicating excellent predictive accuracy. When applied to the institutional cohort, the risk-based algorithm had a sensitivity of 78.3%, specificity of 80.5%, PPV of 7.6%, and NPV of 99.4% for evaluating likelihood of transfusion. Using the algorithm 4,717 T&S tests would have been eliminated (79.3%), resulting in a cost savings of $179,246. Application of the model to the ACS-NSQIP cohort resulted in a sensitivity of 61.9%, specificity of 84.6%, PPV of 15.6%, and NPV of 98.0%.

CONCLUSIONS

The routine use of preoperative ABO/Rh type and antibody screen testing does not appear to be warranted in patients undergoing spine surgery. A risk-based approach to preoperative type and screen testing may eliminate unnecessary tests and generate significant cost savings with minimal disruption to clinical care.

The Use of Critical Care Services After Orthopedic Surgery at a High-Volume Orthopedic Medical Center: A Retrospective Study

Background: With an aging population, orthopedics has become one of the largest and fastest growing surgical fields. However, data on the use of critical care services (CCS) in patients undergoing orthopedic procedures remain sparse. Purpose: We sought to elucidate the prevalence and characteristics of patients requiring CCS and intermediate levels of care after orthopedic surgeries at a high-volume orthopedic medical center. Methods: We retrospectively reviewed inpatient electronic medical record data (2016-2020) at a high-volume orthopedic hospital. Patients who required CCS and intermediate levels of care, including step-down unit (SDU) and telemetry services, were identified. We described characteristics related to patients, procedures, and outcomes, including type of advanced services required and surgery type. Results: Of the 50,387 patients who underwent orthopedic inpatient surgery, 1.6% required CCS and 21.6% were admitted to an SDU. Additionally, 482 (1.0%) patients required postoperative mechanical ventilation and 3602 (7.1%) patients required continuous positive airway pressure therapy. Spine surgery patients were the most likely to require any form of advanced care (45.7%). Conclusions: This retrospective review found that approximately one-fourth of orthopedic surgery patients were admitted to units that provided critical and intermediate levels of care. These results may prove useful to hospitals in estimating needs and allocating resources for advanced and critical care services after orthopedic surgery.

Comparison of Percutaneous Endoscopic Cervical Keyhole Foraminotomy versus Microscopic Anterior Cervical Discectomy and Fusion for Single Level Unilateral Cervical Radiculopathy

Objective

To compare the clinical and radiological outcomes between microscopic anterior cervical discectomy and fusion (ACDF) and percutaneous endoscopic cervical keyhole foraminotomy (PECF) for single level unilateral cervical radiculopathy.

Methods

A total of 127 patients (59 in PECF VS 68 in ACDF) were enrolled in this study from April 2016 to May 2018 with a minimum follow-up of 2 years. Clinical data including baseline data, Neck Disability Index (NDI), and Visual Analogue Scale for neck and arm (VAS-n, VAS-a) were collected and compared. Radiological evaluation such as disc height, ROM of cervical, Cobb’s angle of cervical and Cobb’s angle of operated segment was measured by two experienced radiologists in twice.

Results

There was no significant difference between the two groups in the baseline data, and hospital stay was significantly decreased in PECF group than ACDF group (P < 0.001). PECF group did not yield superior better outcomes in NDI, VAS-a and VAS-n than ACDF group except at 1-month follow-up. As for radiological outcomes, PECF group has significantly better cervical motion, cervical angle and segmental angle than ADCF group at 12- and 24-month follow-up visit (P < 0.05); however, ACDF had shown better disc height restoration and maintenance than PECF (P < 0.05). More complications including surface hematoma and swallowing difficulty were occurred in ADCF group.

Conclusion

Percutaneous endoscopic cervical keyhole foraminotomy could be the alternative method for anterior cervical discectomy and fusion in selective cases. However, the indication should be fulfilled, more studies need to be conducted to further testify the efficacy of PECF.

The influence of social determinants of health on single-level anterior cervical discectomy and fusion outcomes

OBJECTIVE

Methods of reducing complications in individuals electing to undergo anterior cervical discectomy and fusion (ACDF) rely upon understanding at-risk patient populations, among other factors. This study aims to investigate the interplay between social determinants of health (SDOH) and postoperative complication rates, length of stay, revision surgery, and rates of postoperative readmission at 30 and 90 days in individuals electing to have single-level ACDF.

METHODS

Using MARINER30, a database that contains claims information from all payers, patients were identified who underwent single-level ACDF between 2010 and 2019. Identification of patients experiencing disparities in 1 of 6 categories of SDOH was completed using ICD-9 and ICD-10 (International Classifications of Diseases, Ninth and Tenth Revisions) codes. The population was propensity matched into 2 cohorts based on comorbidity status: those with SDOH versus those without.

RESULTS

A total of 10,030 patients were analyzed; there were 5015 (50.0%) in each cohort. The rates of any postoperative complication (12.0% vs 4.6%, p < 0.001); pseudarthrosis (3.4% vs 2.6%, p = 0.017); instrumentation removal (1.8% vs 1.2%, p = 0.033); length of stay (2.54 ± 5.9 days vs 2.08 ± 5.07 days, p < 0.001 [mean ± SD]); and revision surgery (9.7% vs 4.2%, p < 0.001) were higher in the SDOH group compared to patients without SDOH, respectively. Patients with any SDOH had higher odds of perioperative complications (OR 2.8, 95% CI 2.43-3.33), pseudarthrosis (OR 1.3, 95% CI 1.06-1.68), revision surgery (OR 2.4, 95% CI 2.04-2.85), and instrumentation removal (OR 1.4, 95% CI 1.04-2.00).

CONCLUSIONS

In patients who underwent single-level ACDF, there is an association between SDOH and higher complication rates, longer stay, increased need for instrumentation removal, and likelihood of revision surgery.

The Impact of Non-Elective Admission on Cost of Care and Length of Stay in Anterior Cervical Discectomy and Fusion: A Propensity-Matched Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate the impact of admission status on patient outcomes and healthcare costs in anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Undergoing ACDF non-electively has been associated with higher patient comorbidity burdens. However, the impact of non-elective status on the total cost of hospital stay has yet to be quantified.

METHODS

Patients undergoing ACDF at a single institution were placed into elective or non-elective cohorts. Propensity score-matching analysis in a 5:1 ratio controlling for insurance type and comorbidities was used to minimize selection bias. Demographics were compared by univariate analysis. Cost of care, length of stay (LOS), and clinical outcomes were compared between groups using multivariable linear and logistic regression with elective patients as reference cohort. All analyses controlled for sex, preoperative diagnosis, elixhauser comorbidity index (ECI), age, length of surgery, number of segments fused, and insurance type.

RESULTS

Of 708 patients in the final ACDF cohort, 590 underwent an elective procedure and 118 underwent a non-elective procedure. The non-elective group was significantly younger (53.7 vs. 49.5 yr; P = 0.0007). Cohorts had similar proportions of private versus public health insurance, although elective had higher rates of commercial insurance (39.22% vs. 15.25%; P < 0.0001) and non-elective had higher rates of managed care (32.77% vs. 56.78%; P < 0.0001). Operation duration was significantly longer in non-elective patients (158 vs. 177 minutes; P = 0.01). Adjusted analysis also demonstrated that admission status independently affected cost (+$6877, 95% confidence interval [CI]: $4906-$8848; P < 0.0001) and LOS (+4.9 days, 95% CI: 3.9-6.0; P < 0.0001) for the non-elective cohort. The non-elective cohort was significantly more likely to return to the operating room (OR: 3.39; 95% CI: 1.37-8.36, P = 0.0008) and experience non-home discharge (OR: 10.95; 95% CI: 5.00-24.02, P < 0.0001).

CONCLUSION

Patients undergoing ACDF non-electively had higher cost of care and longer LOS, as well as higher rates of postoperative adverse outcomes.Level of Evidence: 3.

Using Predictive Modeling and Supervised Machine Learning to Identify Patients at Risk for Venous Thromboembolism Following Posterior Lumbar Fusion

STUDY DESIGN

Retrospective review.

OBJECTIVE

To use predictive modeling and machine learning to identify patients at risk for venous thromboembolism (VTE) following posterior lumbar fusion (PLF) for degenerative spinal pathology.

METHODS

Patients undergoing single-level PLF in the inpatient setting were identified in the National Surgical Quality Improvement Program database. Our outcome measure of VTE included all patients who experienced a pulmonary embolism and/or deep venous thrombosis within 30-days of surgery. Two different methodologies were used to identify VTE risk: 1) a novel predictive model derived from multivariable logistic regression of significant risk factors, and 2) a tree-based extreme gradient boosting (XGBoost) algorithm using preoperative variables. The methods were compared against legacy risk-stratification measures: ASA and Charlson Comorbidity Index (CCI) using area-under-the-curve (AUC) statistic.

RESULTS

13, 500 patients who underwent single-level PLF met the study criteria. Of these, 0.95% had a VTE within 30-days of surgery. The 5 clinical variables found to be significant in the multivariable predictive model were: age > 65, obesity grade II or above, coronary artery disease, functional status, and prolonged operative time. The predictive model exhibited an AUC of 0.716, which was significantly higher than the AUCs of ASA and CCI (all, P < 0.001), and comparable to that of the XGBoost algorithm (P > 0.05).

CONCLUSION

Predictive analytics and machine learning can be leveraged to aid in identification of patients at risk of VTE following PLF. Surgeons and perioperative teams may find these tools useful to augment clinical decision making risk stratification tool.

Surgery for spinal deformity: non-elective admission status is associated with higher cost of care and longer length of stay

INTRODUCTION

Surgery is commonly indicated for adult spinal deformity. Annual rates and costs of spinal deformity surgery have both increased over the past two decades. However, the impact of non-elective status on total cost of hospitalization and patient outcomes has not been quantified.

OBJECTIVE

To evaluate the impact of admission status on patient outcomes and healthcare costs in spinal deformity surgery.

METHODS

All patients who underwent spinal deformity surgery at a single institution between 2008 and 2016 were grouped by admission status: elective, emergency (ED), or transferred. Demographics were compared by univariate analysis. Cost of care and length of stay (LOS) were compared between admission statuses using multivariable linear regression with elective admissions as reference. Multivariate logistic regression was utilized to assess in-hospital complications, discharge destination, and readmission rates.

RESULTS

There were 427 spinal deformity surgeries included in this study. Compared to elective patients, ED patients had higher Elixhauser Comorbidity Index scores (p < 0.0001), longer LOS (+ 10.9 days, 97.5% CI 6.1-15.6 days, p < 0.0001), and higher costs (+ $20,076, 97.5% CI $9,073-$31,080, p = 0.0008). Transferred patients had significantly higher Elixhauser scores (p = 0.0002), longer LOS (+ 8.8 days, 97.5% CI 3.0-14.7 days, p < 0.0001), and higher rates of non-home discharge (OR = 15.8, 97.5% CI 2.3-110.0, p = 0.001).

CONCLUSION

Patients admitted from the ED undergoing spinal deformity surgery had significantly higher cost of care and longer LOS compared to elective patients. Transferred patients had significantly longer LOS and a higher rate of non-home discharge compared to elective patients.

Comparison of Surgical Outcomes of Microdiskectomy Procedures by Patient Admission Status

OBJECTIVE

We sought to compare the cost and in-hospital outcomes following lumbar microdiskectomy procedures by admission type.

METHODS

Patients undergoing lumbar microdiskectomy at a single institution from 2008 to 2016 following an elective admission (EL) were compared against those who were admitted from the emergency department (ED) or from elsewhere within or outside the hospital system (TR) for their perioperative outcomes and cost. Multivariable modeling controlled for age, sex, self-reported race, Elixhauser comorbidity score, payer type, number of segments, and procedure length.

RESULTS

Of the 1249 patients included in this study, 1116 (89.4%) were admitted electively while 123 (9.8%) were admitted from the ED and 10 (0.8%) were transferred from other hospitals. EL patients had significantly lower comorbidity burdens (P < 0.0001). Univariate and multivariable analyses revealed that transfer admission patients experienced significantly longer hospitalizations (ED: +1.7 days; P < 0.0001; TR: +5.3 days; P < 0.0001) and higher direct costs (ED: $1889; P < 0.0001; TR: $7001; P < 0.0001) compared with EL patients. Despite these risks, ED and TR patients only had increased odds of nonhome discharge compared with EL patients (ED: 3.4; P = 0.002; TR: 7.9; P = 0.02).

CONCLUSIONS

Patients admitted as transfers and from the ED had significantly increased hospitalization lengths of stay and direct costs compared with electively admitted patients.