Hospitalization cost after spine surgery in the United States of America

Liposomal Bupivacaine Reduces Post-Operative Pain and Opioids Consumption in Spine Surgery: A Meta-Analysis of 1,269 Patients

BACKGROUND CONTEXT

Postoperative pain management in spine surgery remains a challenge. Liposomal bupivacaine (LB) has emerged as an alternative or adjunct to opioid-based analgesia. However, existing studies evaluating LB efficacy in spine surgery yield conflicting results and a meta-analysis compiling the literature is lacking.

PURPOSE

The purpose of this meta-analysis was to evaluate pain outcomes, opioid use, and LOS following LB administration after spine surgery STUDY DESIGN: Meta-analysis METHODS: Following the PRISMA guidelines, PubMed, Cochrane, and Google Scholar (pages 1-20) were accessed and explored up to May 2024. Data on medical complications, postoperative pain, postoperative opioid consumption, and length of stay were extracted. Mean differences (MD) with 95% CI were used for continuous data, and odds ratios (OR) were calculated for dichotomous data.

RESULTS

This meta-analysis comprised eleven studies consisting of 1269 patients (677 in the LB group, 592 in the control group). No statistically significant difference was observed in complication rates. The LB group exhibited significantly lower pain scores at postoperative day 2 (MD=-0.31; 95% CI: -0.52- -0.09, p=0.006), lower postoperative opioid consumption (MD=-0.42; 95% CI: -0.79- -0.06, p=0.02), and shorter length of stay (MD=-0.57; 95% CI: -0.94- -0.20, p=0.002).

CONCLUSION

In the immediate postoperative period after spine surgery, the utilization of liposomal bupivacaine was associated with improved pain outcomes, decreased opioid consumption, and shortened length of stay. Although further research is warranted, these findings suggest that LB may offer a valuable adjunct to pain management strategies in patients undergoing spine surgery.

Factors Associated With the Maintenance of Cost-effectiveness at Five Years in Adult Spinal Deformity Corrective Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To evaluate factors associated with the long-term durability of cost-effectiveness (CE) in ASD patients.

BACKGROUND

A substantial increase in costs associated with the surgical treatment for adult spinal deformity (ASD) has given precedence to scrutinize the value and utility it provides.

METHODS

We included 327 operative ASD patients with five-year (5 yr) follow-up. Published methods were used to determine costs based on CMS.gov definitions and were based on the average DRG reimbursement rates. The utility was calculated using quality-adjusted life-years (QALY) utilizing the Oswestry Disability Index (ODI) converted to Short-Form Six-Dimension (SF-6D), with a 3% discount applied for its decline in life expectancy. The CE threshold of $150,000 was used for primary analysis.

RESULTS

Major and minor complication rates were 11% and 47%, respectively, with 26% undergoing reoperation by five years. The mean cost associated with surgery was $91,095±$47,003, with a utility gain of 0.091±0.086 at one years, QALY gained at 2 years of 0.171±0.183, and at five years of 0.42±0.43. The cost per QALY at two years was $414,885, which decreased to $142,058 at five years.With the threshold of $150,000 for CE, 19% met CE at two years and 56% at five years. In those in which revision was avoided, 87% met cumulative CE till life expectancy. Controlling analysis depicted higher baseline CCI and pelvic tilt (PT) to be the strongest predictors for not maintaining durable CE to five years [CCI OR: 1.821 (1.159-2.862), P =0.009] [PT OR: 1.079 (1.007-1.155), P =0.030].

CONCLUSIONS

Most patients achieved cost-effectiveness after four years postoperatively, with 56% meeting at five years postoperatively. When revision was avoided, 87% of patients met cumulative cost-effectiveness till life expectancy. Mechanical complications were predictive of failure to achieve cost-effectiveness at two years, while comorbidity burden and medical complications were at five years.

Surgical Specialty Outcome Differences for Major Spinal Procedures in Low-Acuity Patients

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

There is an ongoing debate as to the influence of specialty training on spine surgery. Alomari et al. indicated the influence of specialty on ACDF procedures. However, deeper analysis into other spine procedures and lower-acuity procedures has yet to occur. In this study, we aim to determine if the outcomes of the low American Society of Anesthesiologists (ASA) classification (ASA 1&2) patients undergoing spine surgery vary based on whether the operating surgeon was an orthopedic surgeon or a neurosurgeon.

METHODS

The NSQIP databases from 2015 to 2021 were queried based on the CPT code for nine common spine procedures. Indicators of surgical course and successful outcomes were documented and compared between specialties.

RESULTS

Neurosurgeons had minimally shorter operative times in the ASA 1&2 combined classification (ASA-C) group for cervical, lumbar, and combined spinal procedural groups. Neurosurgeons had a slightly lower percentage of perioperative transfusions in select ASA-C classes. Orthopedic surgeons had shorter lengths of stay for the cervical groups in ASA-C and ASA-1 classes (ASA-1). However, many specialty differences found in spine patients become less pronounced when considering only ASA-1 patients. Finally, postoperative complication outcomes and re-admission were similar between orthopedic and neurological surgeons in all cases.

CONCLUSIONS

These results, while statistically significant, are very likely clinically insignificant. They demonstrate that both orthopedic surgeons and neurosurgeons perform spinal surgery exceedingly safely with similarly low complication rates. This lays the groundwork for future exploration and benchmarking of performance in spine surgeries across neurosurgery and orthopedics.

Prediction of primary admission total charges following cervical disc arthroplasty utilizing machine learning

BACKGROUND CONTEXT

Cervical disc arthroplasty (CDA) has become an increasingly popular alternative to anterior cervical discectomy and fusion, offering benefits such as motion preservation and reduced risk of adjacent segment disease. Despite its advantages, understanding the economic implications associated with varying patient and hospital factors remains critical.

PURPOSE

To evaluate how hospital size, geographic region, and patient-specific variables influence charges associated with the primary admission period following CDA.

STUDY DESIGN

A retrospective analysis using machine learning models to predict and analyze charge factors associated with CDA.

PATIENT SAMPLE

Data from the National Inpatient Sample (NIS) database from 2016 to 2020 was used, focusing on patients undergoing CDA.

OUTCOME MEASURES

The primary outcome was total charge associated with the primary admission for CDA, analyzed against patient demographics, hospital characteristics, and regional economic conditions.

METHODS

Multivariate linear regression and machine learning algorithms including logistic regression, random forest, and gradient boosting trees were employed to assess their predictive power on charge outcomes. Statistical significance was set at the 0.003 level after applying a Bonferroni correction.

RESULTS

The analysis included 3,772 eligible CDA cases. Major predictors of charge identified were hospital size and ownership type, with large and privately owned hospitals associated with higher charges (p<.001). The Western region of the U.S. also showed significantly higher charges compared to the Northeast (p<.001). The gradient boosting trees model showed the highest accuracy (AUC=85.6%). Length of stay and wage index were significant charge drivers, with each additional inpatient day increasing charges significantly (p<.001) and higher wage index regions correlating with increased charges (p<.001).

CONCLUSIONS

Hospital size, geographic region, and specific patient demographics significantly influence the charges of CDA. Machine learning models proved effective in predicting these charges, suggesting that they could be instrumental in guiding economic decision-making in spine surgery. Future efforts should aim to incorporate these models into broader clinical practice to optimize healthcare spending and enhance patient care outcomes.

A prospective study of lumbar facet arthroplasty in the treatment of degenerative spondylolisthesis and stenosis: cost-effective assessment from the Total Posterior Spine system (TOPSTM) IDE Study: 2-year model revision and sensitivity analyses based on 305 subjects

BACKGROUND CONTEXT

A previous cost-effectiveness analysis published in 2022 found that the Total Posterior Spine (TOPSTM) system was dominant over transforaminal lumbar interbody fusion (TLIF). This analysis required updating to reflect a more complete dataset and pricing considerations.

PURPOSE

To evaluate the cost-effectiveness of TOPSTM system as compared with TLIF based on an updated and complete FDA investigational device exemption (IDE) data set.

STUDY DESIGN/SETTING

Cost-utility analysis of the TOPSTM system compared to TLIF.

PATIENT SAMPLE

A multicenter, FDA IDE, randomized control trial (RCT) investigated the efficacy of TOPSTM compared to TLIF with a current population of n=305 enrolled and n=168 with complete 2-year follow-up.

OUTCOME MEASURES

Cost and quality adjusted life years (QALYs) were calculated to determine our primary outcome measure, the incremental cost-effectiveness ratio. Secondary outcome measures included: net monetary benefit as well at willingness-to-pay (WTP) thresholds.

METHODS

The primary outcome of cost-effectiveness is determined by incremental cost-effectiveness ratio. A Markov model was used to simulate the health outcomes and costs of patients undergoing TOPSTM or TLIF over a 2-year period. alternative scenario sensitivity analysis, one-way sensitivity analysis, and probabilistic sensitivity analysis were conducted to assess the robustness of the model results.

RESULTS

The updated base case result demonstrated that TOPSTM was immediately and longitudinally dominant compared with the control with an incremental cost-effectiveness ratio of -9,637.37 $/QALY. The net monetary benefit was correspondingly $2,237, both from the health system's perspective and at a WTP threshold of 50,000 $/QALY at the 2-year time point. This remained true in all scenarios tested. The Alternative Scenario Sensitivity Analysis suggested cost-effectiveness irrespective of payer type and surgical setting. To remain cost-effective, the cost difference between TOPSTM and TLIF should be no greater than $1,875 and $3,750 at WTP thresholds of $50,000 and 100,000 $/QALY, respectively.

CONCLUSIONS

This updated analysis confirms that the TOPSTM device is a cost-effective and economically dominant surgical treatment option for patients with lumbar stenosis and degenerative spondylolisthesis compared to TLIF in all scenarios examined.

Effectiveness of a Preoperative Bowel Preparation Protocol for Patients With Adolescent Idiopathic Scoliosis to Decrease Postoperative Gastrointestinal Morbidities and the Hospital Length of Stay

STUDY DESIGN

Randomised controlled trial.

OBJECTIVE

This study aimed to determine the effectiveness of a preoperative bowel preparation protocol comprising bisacodyl to minimize postoperative gastrointestinal morbidities and the hospital length of stay for patients with adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Patients who undergo scoliosis correction surgery frequently experience postoperative gastrointestinal morbidities and a prolonged hospital length of stay. Emesis, paralytic ileus and constipation are the most common gastrointestinal morbidities. Opioid medication is a well-known risk factor for gastrointestinal complications after scoliosis correction surgery.

METHODS

Eighty-seven patients (22 boys [25.3%] and 65 girls [74.7%]) with a mean age of 17.7 years (standard deviation [SD], ±2.2 years) diagnosed with adolescent idiopathic scoliosis were enrolled in this study and randomized into 2 groups. Group A comprised 44 patients who received a preoperative bowel preparation comprising bisacodyl. Group B comprised 43 patients who did not receive any preoperative medication. Demographic data, height, weight, medical and surgical comorbidities, Risser status, number of instrumented levels and preoperative opioid consumption of all patients were evaluated.

RESULTS

Group A experienced fewer postoperative abdominal symptoms than group B. The mean hospital length of stay was 4.1 days (SD, ±.6 days; median, 4 days; range, 3-5 days) for group A; however, it was 5.3 days (SD, ±.8 days; median, 5 days; range, 4-7 days) for group B (P = .01).

CONCLUSION

The use of a bowel preparation protocol before scoliosis correction surgery for patients with adolescent idiopathic scoliosis can effectively decrease postoperative gastrointestinal morbidities and the hospital length of stay.

Lumbar Laminotomy: Variables Affecting 90-day Overall Reimbursement

INTRODUCTION

Lumbar laminotomy/diskectomy is a common procedure performed to address radiculopathy that persists despite conservative treatment. Understanding cost/reimbursement variability and its drivers has the potential to help optimize related healthcare delivery. The goal of this study was to assess variability and factors associated with reimbursement through 90 days after single-level lumbar laminotomy/diskectomy.

METHODS

Lumbar laminotomies/diskectomies were isolated from the 2010 to 2021 PearlDiver M151 data set. Exclusion criteria included patients younger than 18 years; other concomitant spinal procedures; and indications of trauma, oncologic, or infectious diagnoses. Patient, surgical, and perioperative data were abstracted. These variables were examined using a multivariable linear regression model with Bonferroni correction to determine factors independently correlated with reimbursement.

RESULTS

A total of 28,621 laminotomies/diskectomies were identified. The average ± standard deviation 90-day postoperative reimbursement was $9,453.83 ± 19,343.99 and, with a non-normal distribution, the median (inner quartile range) was $3,314 ($5,460). By multivariable linear regression, variables associated with greatest increase in 90-day postoperative reimbursement were associated with admission (with the index procedure [+$11,757.31] or readmission [+$31,248.80]), followed by insurance type (relative to Medicare, commercial +$4,183.79), postoperative adverse events (+$2,006.60), and postoperative emergency department visits (+$1,686.89) ( P < 0.0001 for each). Lesser associations were with Elixhauser Comorbidity Index (+$286.67 for each point increase) and age (-$24.65 with each year increase) ( P < 0.001 and P = 0.003, respectively).

DISCUSSION

This study assessed a large cohort of lumbar laminotomies/diskectomies and found substantial variations in reimbursement/cost to the healthcare system. The largest increase in reimbursement was associated with admission (with the index procedure or readmission), followed by insurance type, postoperative adverse events, and postoperative emergency department visits. These results highlight the need to balance inpatient versus outpatient surgeries while limiting postoperative readmissions to minimize the costs associated with healthcare delivery.

The Case for Operative Efficiency in Adult Spinal Deformity Surgery: Impact of Operative Time on Complications, Length of Stay, Alignment, Fusion Rates, and Patient-Reported Outcomes

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the impact of operative room (OR) time in adult spinal deformity (ASD) surgery on patient outcomes.

BACKGROUND

It is currently unknown if OR time in ASD patients matched for deformity severity and surgical invasiveness is associated with patient outcomes.

MATERIALS AND METHODS

ASD patients with baseline and two-year postoperative radiographic and patient-reported outcome measures (PROM) data, undergoing a posterior-only approach for long fusion (>L1-Ilium) were included. Patients were grouped into short OR time (<40th percentile: <359 min) and long OR time (>60th percentile: >421 min). Groups were matched by age, baseline deformity severity, and surgical invasiveness. Demographics, radiographic, PROM data, fusion rate, and complications were compared between groups at baseline and two years follow-up.

RESULTS

In total, 270 patients were included for analysis: the mean OR time was 286 minutes in the short OR group versus 510 minutes in the long OR group ( P <0.001). Age, gender, percent of revision cases, surgical invasiveness, pelvic incidence minus lumbar lordosis, sagittal vertical axis, and pelvic tilt were comparable between groups ( P >0.05). Short OR had a slightly lower body mass index than the short OR group ( P <0.001) and decompression was more prevalent in the long OR time ( P =0.042). Patients in the long group had greater hospital length of stay ( P =0.02); blood loss ( P <0.001); proportion requiring intensive care unit ( P =0.003); higher minor complication rate ( P =0.001); with no significant differences for major complications or revision procedures ( P >0.5). Both groups had comparable radiographic fusion rates ( P =0.152) and achieved improvement in sagittal alignment measures, Oswestry disability index, and Short Form-36 ( P <0.001).

CONCLUSION

Shorter OR time for ASD correction is associated with a lower minor complication rate, a lower estimated blood loss, fewer intensive care unit admissions, and a shorter hospital length of stay without sacrificing alignment correction or PROMs. Maximizing operative efficiency by minimizing OR time in ASD surgery has the potential to benefit patients, surgeons, and hospital systems.

Comparison of the Safety of Inpatient Versus Outpatient Lumbar Fusion : A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic Review and Meta-analysis.

OBJECTIVE

The objective of this study is to synthesize the early data regarding and analyze the safety profile of outpatient lumbar fusion.

SUMMARY OF BACKGROUND DATA

Performing lumbar fusion in an outpatient or ambulatory setting is becoming an increasingly employed strategy to provide effective value-based care. As this is an emerging option for surgeons to employ in their practices, the data is still in its infancy.

METHODS

This study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that described outcomes of inpatient and outpatient lumbar fusion cohorts were searched from PubMed, Medline, The Cochrane Library, and Embase. Rates of individual medical and surgical complications, readmission, and reoperation were collected when applicable. Patient-reported outcomes (PROMs) were additionally collected if reported. Individual pooled comparative meta-analysis was performed for outcomes of medical complications, surgical complications, readmission, and reoperation. PROMs were reviewed and qualitatively reported.

RESULTS

The search yielded 14 publications that compared outpatient and inpatient cohorts with a total of 75,627 patients. Odds of readmission demonstrated no significant difference between outpatient and inpatient cohorts [OR=0.94 (0.81-1.11)]. Revision surgery similarly was no different between the cohorts [OR=0.81 (0.57-1.15)]. Pooled medical and surgical complications demonstrated significantly decreased odds for outpatient cohorts compared with inpatient cohorts [OR=0.58 (0.34-0.50), OR=0.41 (0.50-0.68), respectively]. PROM measures were largely the same between the cohorts when reported, with few studies showing better ODI and VAS Leg outcomes among outpatient cohorts compared with inpatient cohorts.

CONCLUSION

Preliminary data regarding the safety of outpatient lumbar fusion demonstrates a favorable safety profile in appropriately selected patients, with PROMs remaining comparable in this setting. There is no data in the form of prospective and randomized trials which is necessary to definitively change practice.

Risk factors for prolonged length of stay after first single-level lumbar microdiscectomy

OBJECTIVE

The objective is to identify risk factors that potentially prolong the hospital stay in patients after undergoing first single-level open lumbar microdiscectomy.

METHODS

A retrospective single-centre study was conducted. Demographic data, medical records, intraoperative course, and imaging studies were analysed. The outcome measure was defined by the number of days stayed after the operation. A prolonged length of stay (LOS) stay was defined as a minimum of one additional day beyond the median hospital stay in our patient collective. Bivariate analysis and multiple stepwise regression were used to identify independent factors related to the prolonged hospital stay.

RESULTS

Two hundred consecutive patients who underwent first lumbar microdiscectomy between 2018 and 2022 at our clinic were included in this study. Statistical analysis of factors potentially prolonging postoperative hospital stay was done for a total of 24 factors, seven of them were significantly related to prolonged LOS in bivariate analysis. Sex (p = 0.002, median 5 vs. 4 days for females vs. males) and age (rs = 0.35, p ≤ 0.001, N = 200) were identified among the examined demographic factors. Regarding preoperative physical status, preoperative immobility reached statistical significance (p ≤ 0.001, median 5 vs. 4 days). Diabetes mellitus (p = 0.043, median 5 vs. 4 days), anticoagulation and/or antiplatelet agents (p = 0.045, median 5 vs. 4 days), and postoperative narcotic consumption (p ≤ 0.001, median 5 vs. 4 days) as comorbidities were associated with a prolonged hospital stay. Performance of nucleotomy (p = 0.023, median 5 vs. 4 days) was a significant intraoperative factor. After linear stepwise multivariable regression, only preoperative immobility (p ≤ 0.001) was identified as independent risk factors for prolonged length of postoperative hospital stay.

CONCLUSION

Our study identified preoperative immobility as a significant predictor of prolonged hospital stay, highlighting its value in preoperative assessments and as a tool to pinpoint at-risk patients. Prospective clinical trials with detailed assessment of mobility, including grading, need to be done to verify our results.

Does Surgical Day of the Week Affect Hospital Course and Outcomes for Patients Undergoing Adult Spinal Deformity Surgery?

STUDY DESIGN

Retrospective Cohort Analysis.

OBJECTIVES

Extended hospital length of stay (LOS) poses a significant cost burden to patients undergoing adult spinal deformity (ASD) surgery. The purpose of this study is to investigate the relationship between late-week surgery and LOS in patients undergoing ASD surgery.

METHODS

256 patients who underwent ASD surgery between January 2018 and December 2021 by a single fellowship-trained orthopedic spine surgeon comprised the patient sample. Demographics, intraoperative, and perioperative data were collected for the 256 patients who underwent ASD surgery. Patients were divided into two groups based on surgical day of the week: (1) Early-week (Monday/Tuesday) n = 126 and (2) Late-week (Thursday/Friday) n = 130. Descriptive statistics, T-tests, and linear and logistic regression models were used to analyze the data.

RESULTS

Surgical details and sociodemographic characteristics did not differ between the groups. When controlling for TLIF/DLIF status and PSO status there was no difference in mean length of stay between the groups. The late-week group was associated with a greater risk of 30-day readmission, but there was no difference in complications, infections, or intraoperative complications.

CONCLUSIONS

We found no difference in mean length of stay between surgeries performed early in the week vs late in the week. Although late-week surgeries had higher 30-day readmission risk, all other outcomes, including complication rates, showed no significant differences. When adequate weekend post-operative care is available, we do not advise restricting ASD surgeries to specific weekdays.

The effect of cannabis use on postoperative complications in patients undergoing spine surgery: A national database study

Background

With the increased use of cannabis in the US, there is a significant need to understand the medical complications associated with its use in relationship to a surgical population. Cannabis has mainly been studied with respect to its qualities of pain treatment, yet few studies have investigated post-surgical complications associated with its use. Therefore, the purpose of this study was to explore the effect of cannabis use on complications in spine surgery, and compare these complications rates to opioid-related complications.

Methods

This was a retrospective study conducted using the PearlDiver Database. Using ICD codes 40,989 patients that underwent lumbar spine fusion between January 2010 and October 2020 were identified and divided into 3 study groups (i.e., control, patients with known opioid use disorder, and patients identified as cannabis users). Differences in the incidence of complications within 30 days of the index procedure and pseudarthrosis rates at 18 months postindex procedure were assessed among study groups using a multivariate logistic regression.

Results

Of 12.4% study population used cannabis and 38.8% had a known opioid use disorder. Results indicated increased odds of experiencing a VTE, hypoxia, myocardial infarction, and arrhythmia for both opioid and cannabis users compared to controls; however, when controlling for tobacco use there were no increased odds of complications within the cannabis group. The pseudarthrosis rate was greater in cannabis users (2.4%) than in controls (1.1%).

Conclusions

The pseudarthrosis rate was significantly greater in patients using cannabis and opioids compared to the control group. However, when controlling for tobacco use, results suggested a possible negative synergistic between cannabis use and concomitant tobacco use that may influence bone fusion.

Total Knee Arthroplasty: Variables Affecting 90-day Overall Reimbursement

BACKGROUND

Total knee arthroplasty (TKA) is commonly considered to address symptomatically limiting knee osteoarthritis. With increasing utilization, understanding the variability and related drivers may help the healthcare system optimize delivery to the large numbers of patient to whom it is offered.

METHODS

A total of 1,066,327 TKA patients who underwent primary TKA were isolated from a 2010 to 2021 PearlDiver national dataset. Exclusion criteria included patients less than 18 years old and traumatic, infectious, or oncologic indications. Overall, 90-day reimbursements and variables associated with the patient, surgical procedure, region, and perioperative period were abstracted. Multivariable linear regressions were performed to determine independent drivers of reimbursement.

RESULTS

The 90-day postoperative reimbursements had an average (standard deviation) of $11,212.99 ($15,000.62), a median (interquartile range) of $4,472.00 ($13,101.00), and a total of $11,946,962,912. Variables independently associated with the greatest increase in overall 90-day reimbursement were related to admission (in-patient index-procedure [+$5,695.26] or hospital readmission [+$18,495.03]). Further drivers were region (Midwest +$8,826.21, West +$4,578.55, South +$3,709.40; relative to Northeast), insurance (commercial +$4,492.34, Medicaid +$1,187.65; relative to Medicare), postoperative emergency department visits (+$3,574.57), postoperative adverse events (+$1,309.35), (P < .0001 for each).

CONCLUSION

The current study assessed over a million TKA patients and found large variations in reimbursement/cost. The largest increases in reimbursement were associated with admission (readmission or index procedure). This was followed by region, insurance, and other postoperative events. These results underscore the necessity to balance performing out-patient surgeries in appropriate patients versus the risk of readmissions and defined other areas for cost containment strategies.

Effect of Instrumented Spine Surgery on Length of Stay

INTRODUCTION

Total joint arthroplasty studies have identified that surgeries that take place later in the week have a longer length of stay compared with those earlier in the week. This has not been demonstrated in studies focused on anterior cervical diskectomy and fusions or minimally invasive lumbar laminectomies. All-inclusive instrumented spine surgeries, however, have not been analyzed. The purpose of this study was to determine whether day of surgery affects length of stay and whether there are predictive patient characteristics that affect length of stay in instrumented spine surgery.

METHODS

All instrumented spine surgeries in 2019 at a single academic tertiary center were retrospectively reviewed. Patients were categorized for surgical day and discharge disposition to home or a rehabilitation facility. Differences by patient characteristics in length of stay and discharge disposition were compared using Kruskal-Wallis and chi square tests along with multiple comparisons.

RESULTS

Seven hundred six patients were included in the analysis. Excluding Saturday, there were no differences in length of stay based on the day of surgery. Age older than 75 years, female, American Society of Anesthesiology (ASA) classification of 3 or 4, and an increased Charlson Comorbidity Index were all associated with a notable increase in length of stay. While most of the patients were discharged home, discharge to a rehabilitation facility stayed, on average, 4.7 days longer (6.8 days compared with 2.1 days, on average) and were associated with an age older than 66 years old, an ASA classification of 3 or 4, and a Charlson Comorbidity Index of 1 to 3.

CONCLUSIONS

Day of surgery does not affect length of stay in instrumented spine surgeries. Discharge to a rehabilitation facility, however, did increase the length of stay as did age older than 75 years, higher ASA classification, and increased Charlson Comorbidity Index classification.

Risk factors for extended length of stay and non-home discharge in adults treated with multi-level fusion for lumbar degenerative pathology and deformity

PURPOSE

To identify independent risk factors, including the Risk Assessment and Prediction Tool (RAPT) score, associated with extended length of stay (eLOS) and non-home discharge following elective multi-level instrumented spine fusion operations for diagnosis of adult spinal deformity (ASD) and lumbar degenerative pathology.

METHODS

Adults who underwent multi-level ([Formula: see text] segments) instrumented spine fusions for ASD and lumbar degenerative pathology at a single institution (2016-2021) were reviewed. Presence of a pre-operative RAPT score was used as an inclusion criterion. Excluded were patients who underwent non-elective operations, revisions, operations for trauma, malignancy, and/or infections. Outcomes were eLOS (> 7 days) and discharge location (home vs. non-home). Predictor variables included demographics, comorbidities, operative information, Surgical Invasiveness Index (SII), and RAPT score. Fisher's exact test was used for univariate analysis, and significant variables were implemented in multivariate binary logistic regression, with generation of 95% percent confidence intervals (CI), odds ratios (OR), and p-values.

RESULTS

Included for analysis were 355 patients. Post-operatively, 36.6% (n = 130) had eLOS and 53.2% (n = 189) had a non-home discharge. Risk factors significant for a non-home discharge were older age (> 70 years), SII > 36, pre-op RAPT < 10, DMII, diagnosis of depression or anxiety, and eLOS. Risk factors significant for an eLOS were SII > 20, RAPT < 6, and an ASA score of 3.

CONCLUSION

The RAPT score and SII were most important significant predictors of eLOS and non-home discharges following multi-level instrumented fusions for lumbar spinal pathology and deformity. Preoperative optimization of the RAPT's individual components may provide a useful strategy for decreasing LOS and modifying discharge disposition.

Artificial Learning and Machine Learning Applications in Spine Surgery: A Systematic Review

OBJECTIVES

This current systematic review sought to identify and evaluate all current research-based spine surgery applications of AI/ML in optimizing preoperative patient selection, as well as predicting and managing postoperative outcomes and complications.

METHODS

A comprehensive search of publications was conducted through the EMBASE, Medline, and PubMed databases using relevant keywords to maximize the sensitivity of the search. No limits were placed on level of evidence or timing of the study. Findings were reported according to the PRISMA guidelines.

RESULTS

After application of inclusion and exclusion criteria, 41 studies were included in this review. Bayesian networks had the highest average AUC (.80), and neural networks had the best accuracy (83.0%), sensitivity (81.5%), and specificity (71.8%). Preoperative planning/cost prediction models (.89,82.2%) and discharge/length of stay models (.80,78.0%) each reported significantly higher average AUC and accuracy compared to readmissions/reoperation prediction models (.67,70.2%) (P < .001, P = .005, respectively). Model performance also significantly varied across postoperative management applications for average AUC and accuracy values (P < .001, P < .027, respectively).

CONCLUSIONS

Generally, authors of the reviewed studies concluded that AI/ML offers a potentially beneficial tool for providers to optimize patient care and improve cost-efficiency. More specifically, AI/ML models performed best, on average, when optimizing preoperative patient selection and planning and predicting costs, hospital discharge, and length of stay. However, models were not as accurate in predicting postoperative complications, adverse events, and readmissions and reoperations. An understanding of AI/ML-based applications is becoming increasingly important, particularly in spine surgery, as the volume of reported literature, technology accessibility, and clinical applications continue to rapidly expand.

Factors Causing Delay in Discharge in Patients Eligible for Ambulatory Lumbar Fusion Surgery

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the postoperative factors that led delayed discharge in patients who would have been eligible for ambulatory lumbar fusion (ALF).

SUMMARY OF BACKGROUND DATA

Assessing postoperative inefficiencies is vital to increase the feasibility of ALF.

MATERIALS AND METHODS

Patients who underwent single-level minimally invasive transforaminal lumbar interbody fusion and would have met the eligibility criteria for ALF were included. Length of stay (LOS); time in postanesthesia recovery unit (PACU); alertness and neurological examination, and pain scores at three and six hours; type of analgesia; time to physical therapy (PT) visit; reasons for PT nonclearance; time to per-oral (PO) intake; time to voiding; time to readiness for discharge were assessed. Time taken to meet each discharge criterion was calculated. Multiple regression analyses were performed to study the effect of variables on postoperative parameters influencing discharge.

RESULTS

Of 71 patients, 4% were discharged on the same day and 69% on postoperative day 1. PT clearance was the last-met discharge criterion in 93%. Sixty-six percent did not get PT evaluation on the day of surgery. Seventy-six percent required intravenous opioids and <60% had adequate pain control. Twenty-six percent had orthostatic intolerance. The median postoperative LOS was 26.9 hours, time in PACU was 4.2 hours, time to PO intake was 6.5 hours, time to first void was 6.3 hours, time to first PT visit was 17.7 hours, time to PT clearance was 21.8 hours, and time to discharge readiness was 21.9 hours. Regression analysis showed that time to PT clearance, time to PO intake, time to voiding, time in PACU, and pain score at three hours had a significant effect on LOS.

CONCLUSIONS

Unavailability of PT, surgery after 1  pm , orthostatic intolerance, inadequate pain control, prolonged PACU stay, and long feeding and voiding times were identified as modifiable factors preventing same-day discharge.

LEVEL OF EVIDENCE

4.

Comparison of Lumbar Fusion With and Without Interbody Fusion for Lumbar Stenosis Using Patient-Reported Outcomes Measurement Information System (PROMIS) Computer Adaptive Testing (CAT)

Study design

This was a retrospective analysis of patient-reported outcomes across a two-year period.

Summary of background data

Patients suffering from lumbar stenosis may experience low back pain, neurogenic claudication, and weakness. Patients can benefit from surgical intervention, including decompression with or without fusion. However, the superiority of any single fusion construct remains controversial.

Objective

The goal of this study was to compare Patient-Reported Outcomes Measurement Information System (PROMIS®) Computer Adaptive Testing (CAT) measures in patients with lumbar spinal stenosis treated surgically with lumbar decompression and fusion with or without interbody fusion.

Methods

A retrospective review of patients with lumbar stenosis undergoing lumbar decompression and one-level fusion was performed. PROMIS® CAT Physical Function (PF) and Pain Interference (PI) assessments were administered using a web-based platform pre and postoperatively.

Results

Sixty patients with lumbar stenosis undergoing one-level lumbar fusion were identified. Twenty-seven patients underwent posterior lumbar fusion (PSF) alone and 33 underwent one-level lumbar interbody fusion (IF). Patients undergoing IF had better absolute PF scores compared to patients undergoing PSF at one-year postoperatively (48.9 v 41.6, p=0.002) and greater relative improvement in PF scores from baseline at one-year postoperatively (D13.6 v D8.6, p=0.02). A subgroup analysis of patients undergoing TLIF v PSF showed better absolute PF scores at the one-year follow-up in the TLIF group (47.1 v 42.3, p=0.04). No differences were found in PI scores at any time point between the PSF and IF groups. Patients undergoing IF had significantly shorter hospital stays (2.5 v 3.3 days, p=0.02) compared to patients undergoing PSF.

Conclusions

Patients with lumbar spinal stenosis treated with one-level IF reported higher absolute PF scores and experienced greater relative improvement in PF scores from baseline at one-year follow-up compared to patients treated with PSF alone. Additionally, IF is associated with a decreased length of hospital stay as compared to PSF.

Frailty Status Is a More Robust Predictor Than Age of Spinal Tumor Surgery Outcomes: A NSQIP Analysis of 4,662 Patients

Objective

The present study aimed to evaluate the effect of baseline frailty status (as measured by modified frailty index-5 [mFI-5]) versus age on postoperative outcomes of patients undergoing surgery for spinal tumors using data from a large national registry.

Methods

The National Surgical Quality Improvement Program database was used to collect spinal tumor resection patients’ data from 2015 to 2019 (n = 4,662). Univariate and multivariate analyses for age and mFI-5 were performed for the following outcomes: 30-day mortality, major complications, unplanned reoperation, unplanned readmission, hospital length of stay (LOS), and discharge to a nonhome destination. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminative performance of age versus mFI-5.

Results

Both univariate and multivariate analyses demonstrated that mFI-5 was a more robust predictor of worse postoperative outcomes as compared to age. Furthermore, based on categorical analysis of frailty tiers, increasing frailty was significantly associated with increased risk of adverse outcomes. ‘Severely frail’ patients were found to have the highest risk, with odds ratio 16.4 (95% confidence interval [CI],11.21–35.44) for 30-day mortality, 3.02 (95% CI, 1.97–4.56) for major complications, and 2.94 (95% CI, 2.32–4.21) for LOS. In ROC curve analysis, mFI-5 score (area under the curve [AUC] = 0.743) achieved superior discrimination compared to age (AUC = 0.594) for mortality.

Conclusion

Increasing frailty, as measured by mFI-5, is a more robust predictor as compared to age, for poor postoperative outcomes in spinal tumor surgery patients. The mFI-5 may be clinically used for preoperative risk stratification of spinal tumor patients.

Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs

STUDY DESIGN

Retrospective study of a prospective multicenter database.

OBJECTIVE

The purpose of this study was to identify predictors of lower total surgery costs at 3 years for adult spinal deformity (ASD) patients.

SUMMARY OF BACKGROUND DATA

ASD surgery involves complex deformity correction.

METHODS

Inclusion criteria: surgical ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥25°, or thoracic kyphosis ≥60°) patients >18 years. Total costs for surgery were calculated using the PearlDiver database. Cost per quality-adjusted life year was assessed. A Conditional Variable Importance Table used nonreplacement sampling set of 20,000 Conditional Inference trees to identify top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) SRS Schwab SVA grades.

RESULTS

Three hundred sixtee of 322 ASD patients met inclusion criteria. At 3-year follow up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. The average costs of surgery at 3 years was found to be $72,947.87, with no significant difference in costs between deformity groups (P > 0.05). There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, the top predictors of lower costs were frailty scores <0.19, baseline (BL) SRS Activity >1.5, BL Oswestry Disability Index <50 (all P < 0.05). For LSVA patients, no history of osteoporosis, SRS Activity scores >1.5, age <64, were the top predictors of lower costs (all P < 0.05). Among MSVA patients, ASD invasiveness scores <94.16, no past history of cancer, and frailty scores <0.3 trended toward lower total costs (P = 0.071, P = 0.210). For HSVA, no history of smoking and body mass index <27.8 trended toward lower costs (both P = 0.060).

CONCLUSION

ASD surgery has the potential for improved cost efficiency, as costs ranged from $57,606.88 to $116,312.54. Predictors of lower costs included higher BL SRS activity, decreased frailty, and not having depression. Additionally, predictors of lower costs were identified for different BL deformity profiles, allowing for the optimization of cost efficiency for all patients.Level of Evidence: 3.

Postoperative Urinary Retention Following Thoracolumbosacral Spinal Fusion: Prevalence, Risk Factors, and Outcomes

Objective

Postoperative urinary retention (POUR) is an often-underestimated common complication following spine surgery, and it is essential to avoid its untoward long-term consequences. Besides, a dilemma exists regarding the appropriate timing for the postoperative removal of indwelling catheter (IDC). Hence, we aim to describe the prevalence, risk factors, and outcomes of POUR and also come up with recommendations for the removal of IDC.

Methods

Electronic records of patients who underwent elective thoracolumbosacral spinal fusion surgery from January 2017 to December 2019 were retrospectively reviewed. Excluded were those who underwent fusion for indications such as trauma, cauda equina syndrome, infection, and malignancy. Both surgery-related and patient-related risk factors were tabulated, and their association with the likely development of POUR was assessed by univariate and multivariate analysis.

Results

One hundred sixty-eight patients (median age=64.1 years; 58.9% female) were included, with the incidence of POUR being 7.8%. Our findings suggest surgery-related factors, both intra- and postoperative, including operating time (p=0.008), anesthetic time (p=0.005), number of fusion levels (p<0.001), mobilization status prior to trial off catheter (TOC; p=0.021), and TOC timing (p=0.029) may have an association with POUR. In addition, patient-related factors, including the use of beta-blockers (p=0.020) and pre-operative mobility status (p<0.001), may also be associated with the likely development of POUR.

Conclusion

POUR seems to be a frequent complication following thoracolumbosacral spinal fusion surgery, which was found to have an association with some surgery-related and patient-related factors. While most of these factors are non-modifiable, certain modifiable risk factors provide the surgeon an opportunity to prevent POUR. Considering these factors, we recommend appropriate and timely mobilization of the patient prior to removal of IDC, which is to be performed preferably in the daytime.

Frequency and Implications of Concurrent Complications Following Adult Spinal Deformity Corrective Surgery

STUDY DESIGN

Retrospective review.

OBJECTIVE

Identify co-occurring perioperative complications and associated predictors in a population of patients undergoing surgery for adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

Few studies have investigated the development of multiple, co-occurring complications following ASD-corrective surgery. Preoperative risk stratification may benefit from identification of factors associated with multiple, co-occurring complications.

METHODS

Elective ASD patients in National Surgical Quality Improvement Program (NSQIP) 2005 to 2016 were isolated; rates of co-occurring complications and affected body systems were assessed via cross tabulation. Random forest analysis identified top patient and surgical factors associated with complication co-occurrence, using conditional inference trees to identify significant cutoff points. Binary logistic regression indicated effect size of top influential factors associated with complication co-occurrence at each factor's respective cutoff point.

RESULTS

Included: 6486 ASD patients. The overall perioperative complication rate was 34.8%; 28.5% of patients experienced one complication, 4.5% experienced two, and 1.8% experienced 3+. Overall, 11% of complication co-occurrences were pulmonary/cardiovascular, 9% pulmonary/renal, and 4% integumentary/renal. By complication type, the most common co-occurrences were transfusion/urinary tract infection (UTI) (24.3%) and transfusion/pneumonia (17.7%). Surgical factors of operative time ≥400 minutes and fusion ≥9 levels were the strongest factors associated with the incidence of co-occurring complications, followed by patient-specific variables like American Society of Anesthesiologists (ASA) physical status classification grade ≥2 and age ≥65 years. Regression analysis further showed associations between increasing complication number and longer length of stay (LOS), (R2 = 0.202, P < 0.001), non-home discharge (R2 = 0.111, P = 0.001), and readmission (R2 = 0.010, P < 0.001).

CONCLUSION

For surgical ASD patients, the overall rate of co-occurring perioperative complications was 6.3%. Body systems most commonly affected by complication co-occurrences were pulmonary and cardiovascular, and common co-occurrences included transfusion/UTI (24.3%) and transfusion/pneumonia (17.7%). Increasing number of perioperative complications was associated with greater LOS, non-home discharge, and readmission, highlighting the importance of identifying risk factors for complication co-occurrences.Level of Evidence: 3.

Impact of Insurance Provider on Postoperative Hospital Length of Stay After Spine Surgery

OBJECTIVE

Differences in insurer and payer status have been shown to increase patient hospital length of stay (LOS) by delaying the approval of transfer to a rehabilitation facility. The aim of the current study is to determine the impact of the type of insurance provider on postoperative hospital LOS after spine surgery.

METHODS

In our single-institution retrospective study, all patients undergoing elective spine surgery between August 2018 and August 2019 as part of an enhanced recovery after surgery (ERAS) protocol were enrolled in a prospectively collected registry. Insurance payer type was analyzed to determine its effect on total patient LOS after surgery.

RESULTS

A total of 106 patients were included in the study. Insurance payers studied were Medicare, private insurers (preferred provider organization and health maintenance organization), and the Veterans Affairs payer TriWest. Patients in all groups had comparable demographic characteristics and procedural variables. There was a statistically significant difference in days stayed beyond medical clearance among the 3 insurance provider groups (P < 0.001); TriWest patients stayed an average of 3.2 days beyond clearance, compared with private insurance (1.2 days) and Medicare (0.3 days). Individual subanalysis of the ERAS complex pathway population mirrored these findings.

CONCLUSIONS

Hospitalization beyond medical clearance after spine surgery follows a predictable pattern regardless of ERAS pathway complexity, with Medicare having a shorter delay in approving patient progression than private insurance, which has less of a delay than Triwest.

A Risk-Benefit Analysis of Increasing Surgical Invasiveness Relative to Frailty Status in Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective review of a prospectively enrolled multicenter Adult Spinal Deformity (ASD) database.

OBJECTIVE

Investigate invasiveness and outcomes of ASD surgery by frailty state.

SUMMARY OF BACKGROUND DATA

The ASD Invasiveness Index incorporates deformity-specific components to assess correction magnitude. Intersections of invasiveness, surgical outcomes, and frailty state are understudied.

METHODS

ASD patients with baseline and 3-year (3Y) data were included. Logistic regression analyzed the relationship between increasing invasiveness and major complications or reoperations and meeting minimal clinically important differences (MCID) for health-related quality-of-life measures at 3Y. Decision tree analysis assessed invasiveness risk-benefit cutoff points, above which experiencing complications or reoperations and not reaching MCID were higher. Significance was set to P < 0.05.

RESULTS

Overall, 195 of 322 patients were included. Baseline demographics: age 59.9 ± 14.4, 75% female, BMI 27.8 ± 6.2, mean Charlson Comorbidity Index: 1.7 ± 1.7. Surgical information: 61% osteotomy, 52% decompression, 11.0 ± 4.1 levels fused. There were 98 not frail (NF), 65 frail (F), and 30 severely frail (SF) patients. Relationships were found between increasing invasiveness and experiencing a major complication or reoperation for the entire cohort and by frailty group (all P < 0.05). Defining a favorable outcome as no major complications or reoperation and meeting MCID in any health-related quality of life at 3Y established an invasiveness cutoff of 63.9. Patients below this threshold were 1.8[1.38-2.35] (P < 0.001) times more likely to achieve favorable outcome. For NF patients, the cutoff was 79.3 (2.11[1.39-3.20] (P < 0.001), 111 for F (2.62 [1.70-4.06] (P < 0.001), and 53.3 for SF (2.35[0.78-7.13] (P = 0.13).

CONCLUSION

Increasing invasiveness is associated with increased odds of major complications and reoperations. Risk-benefit cutoffs for successful outcomes were 79.3 for NF, 111 for F, and 53.3 for SF patients. Above these, increasing invasiveness has increasing risk of major complications or reoperations and not meeting MCID at 3Y.Level of Evidence: 3.

Recent Trends in Medicare Utilization and Reimbursement for Orthopaedic Procedures Performed at Ambulatory Surgery Centers

BACKGROUND

As part of a market-driven response to the increasing costs of hospital-based surgical care, an increasing volume of orthopaedic procedures are being performed in ambulatory surgery centers (ASCs). The purpose of the present study was to identify recent trends in orthopaedic ASC procedure volume, utilization, and reimbursements in the Medicare system between 2012 and 2017.

METHODS

This cross-sectional, national study tracked annual Medicare claims and payments and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates, and reimbursement rates, and to identify demographic predictors of ASC utilization.

RESULTS

A total of 1,914,905 orthopaedic procedures were performed at ASCs in the Medicare population between 2012 and 2017, with an 8.8% increase in annual procedure volume and a 10.5% increase in average reimbursements per case. ASC orthopaedic procedure utilization, including utilization across all subspecialties, is strongly associated with metropolitan areas compared with rural areas. In addition, orthopaedic procedure utilization, including for sports and hand procedures, was found to be significantly higher in wealthier counties (measured by average household income) and in counties located in the South.

CONCLUSIONS

This study demonstrated increasing orthopaedic ASC procedure volume in recent years, driven by increases in hand procedure volume. Medicare reimbursements per case have steadily risen and outpaced the rate of inflation over the study period. However, as orthopaedic practice overhead continues to increase, other Medicare expenditures such as hospital payments and operational and implant costs also must be evaluated. These findings may provide a source of information that can be used by orthopaedic surgeons, policy makers, investors, and other stakeholders to make informed decisions regarding the costs and benefits of the use of ASCs for orthopaedic procedures.

Systematic review and meta-analysis of the clinical utility of Enhanced Recovery After Surgery pathways in adult spine surgery

OBJECTIVE

Spine surgery has been identified as a significant source of healthcare expenditures in the United States. Prolonged hospitalization has been cited as one source of increased spending, and there has been drive from providers and payors alike to decrease inpatient stays. One strategy currently being explored is the use of Enhanced Recovery After Surgery (ERAS) protocols. Here, the authors review the literature on adult spine ERAS protocols, focusing on clinical benefits and cost reductions. They also conducted a quantitative meta-analysis examining the following: 1) length of stay (LOS), 2) complication rate, 3) wound infection rate, 4) 30-day readmission rate, and 5) 30-day reoperation rate.

METHODS

Using the PRISMA guidelines, a search of the PubMed/Medline, Web of Science, Cochrane Reviews, Embase, CINAHL, and OVID Medline databases was conducted to identify all full-text articles in the English-language literature describing ERAS protocol implementation for adult spine surgery. A quantitative meta-analysis using random-effects modeling was performed for the identified clinical outcomes using studies that directly compared ERAS protocols with conventional care.

RESULTS

Of 950 articles reviewed, 34 were included in the qualitative analysis and 20 were included in the quantitative analysis. The most common protocol types were general spine surgery protocols and protocols for lumbar spine surgery patients. The most frequently cited benefits of ERAS protocols were shorter LOS (n = 12), lower postoperative pain scores (n = 6), and decreased complication rates (n = 4). The meta-analysis demonstrated shorter LOS for the general spine surgery (mean difference -1.22 days [95% CI -1.98 to -0.47]) and lumbar spine ERAS protocols (-1.53 days [95% CI -2.89 to -0.16]). Neither general nor lumbar spine protocols led to a significant difference in complication rates. Insufficient data existed to perform a meta-analysis of the differences in costs or postoperative narcotic use.

CONCLUSIONS

Present data suggest that ERAS protocol implementation may reduce hospitalization time among adult spine surgery patients and may lead to reductions in complication rates when applied to specific populations. To generate high-quality evidence capable of supporting practice guidelines, though, additional controlled trials are necessary to validate these early findings in larger populations.

Utilization of the American Society of Anesthesiologists (ASA) classification system in evaluating outcomes and costs following deformity spine procedures

PURPOSE

Adult spinal deformity (ASD) has increased prevalence in aging populations. Due to the high cost of surgery, studies have evaluated risk factors that predict readmissions and poor outcomes. The American Society of Anesthesiologists (ASA) classification system has been applied to patients with ASD to assess preoperative health and assess the correlation between ASA class and postoperative complications. This study evaluates the relationship between ASA and complications, length of stay (LOS), and direct costs following spine deformity surgery.

METHODS

Patients undergoing spine deformity surgery at a single institution from 2008-2016 were included and stratified based upon ASA status. Primary outcomes included patient demographics, adjusted LOS, and cost of care. Secondary measures compared between cohorts included adverse events, non-home discharge, and readmission rates.

RESULTS

442 patients with ASD were included in this study. Higher ASA class was correlated with greater Elixhauser Comorbidity Index (ECI) scores (p < 0.0001) and older age (p < 0.0001). Univariate analysis showed longer LOS (p < 0.0001) and greater direct costs in patients with higher ASA class (p < 0.0001). Patients in ASA Class III or IV had the greatest incidence of ICU stay when compared to patients without systemic disease (p < 0.0001). Upon multivariable regression analysis, high ASA class was associated with higher rates of non-home discharge (OR 5.0, 95% CI 3.1-8.1). Direct costs were greater for higher ASA class (regression estimate =  + $9,666, p = 0.002).

CONCLUSION

This study demonstrates that ASA class is correlated with a more complicated postoperative hospital course, greater rates of non-home discharge, total direct costs in spine deformity patients.

Does day of surgery affect length of stay and hospital charges following lumbar decompression?

Study Design:

This is a retrospective cohort study.

Introduction:

Spine procedures are the most expensive surgical interventions on a per-case basis. Previously, orthopedic procedures occurring later in the week have been associated with an increased length of stay (LOS) and consequent increase in costs. However, no such analysis has been performed on common spinal procedures such as minimally invasive lumbar decompression (MIS LD). The purpose of this study is to determine if there is an association between day of surgery and LOS or direct hospital costs after MIS LD.

Materials and Methods:

A prospectively maintained surgical database of patients who underwent primary, single, or multilevel MIS LD for degenerative spinal pathology between 2008 and 2017 was reviewed. Patients undergoing MIS LD were grouped as early in the week (Monday/Tuesday) or late in the week (Thursday/Friday). Differences in patient demographics and preoperative characteristics were compared using χ 2 analysis or Student’s t-test. Associations between date of surgery, LOS, and costs were assessed using multivariate linear regression.

Results:

A total of 717 patients were included. Of these, 420 (58.6%) were in the early surgery cohort and 297 (41.4%) were in the late surgery cohort. There were no differences in demographic characteristics, operative levels, operative time, blood loss, or hospital LOS between cohorts ( p > 0.05). Furthermore, there was no difference in total direct costs or specific cost categories between cohorts ( p > 0.05).

Discussion:

The timing of surgery within the week is not associated with differences in inpatient LOS or hospital costs following MIS LD. As such, hospitals should not alter surgical scheduling patterns to restrict these procedures to certain days within the week.

Institutional databases may underestimate the risk factors for 30-day unplanned readmissions compared to national databases

OBJECTIVE

The National Surgical Quality Improvement Program (NSQIP) and National Readmissions Database (NRD) are two widely used databases for research studies. However, they may not provide generalizable information in regard to individual institutions. Therefore, the objective of the present study was to evaluate 30-day readmissions following anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF) procedures by using these two national databases and an institutional cohort.

METHODS

The NSQIP and NRD were queried for patients undergoing elective ACDF and PLF, with the addition of an institutional cohort. The outcome of interest was 30-day readmissions following ACDF and PLF, which were unplanned and related to the index procedure. Subsequently, univariable and multivariable analyses were conducted to determine the predictors of 30-day readmissions by using both databases and the institutional cohort.

RESULTS

Among all identified risk factors, only hypertension was found to be a common risk factor between NRD and the institutional cohort following ACDF. NSQIP and the institutional cohort both showed length of hospital stay to be a significant predictor for 30-day related readmission following PLF. There were no overlapping variables among all 3 cohorts for either ACDF or PLF. Additionally, the national databases identified a greater number of risk factors for 30-day related readmissions than did the institutional cohort for both procedures.

CONCLUSIONS

Overall, significant differences were seen among all 3 cohorts with regard to top predictors of 30-day unplanned readmissions following ACDF and PLF. The higher quantity of significant predictors found in the national databases may suggest that looking at single-institution series for such analyses may result in underestimation of important variables affecting patient outcomes, and that big data may be helpful in addressing this concern.

Utility of the Hospital Frailty Risk Score for Predicting Adverse Outcomes in Degenerative Spine Surgery Cohorts

BACKGROUND

As spine surgery becomes increasingly common in the elderly, frailty has been used to risk stratify these patients. The Hospital Frailty Risk Score (HFRS) is a novel method of assessing frailty using International Classification of Diseases, Tenth Revision (ICD-10) codes. However, HFRS utility has not been evaluated in spinal surgery.

OBJECTIVE

To assess the accuracy of HFRS in predicting adverse outcomes of surgical spine patients.

METHODS

Patients undergoing elective spine surgery at a single institution from 2008 to 2016 were reviewed, and those undergoing surgery for tumors, traumas, and infections were excluded. The HFRS was calculated for each patient, and rates of adverse events were calculated for low, medium, and high frailty cohorts. Predictive ability of the HFRS in a model containing other relevant variables for various outcomes was also calculated.

RESULTS

Intensive care unit (ICU) stays were more prevalent in high HFRS patients (66%) than medium (31%) or low (7%) HFRS patients. Similar results were found for nonhome discharges and 30-d readmission rates. Logistic regressions showed HFRS improved the accuracy of predicting ICU stays (area under the curve [AUC] = 0.87), nonhome discharges (AUC = 0.84), and total complications (AUC = 0.84). HFRS was less effective at improving predictions of 30-d readmission rates (AUC = 0.65) and emergency department visits (AUC = 0.60).

CONCLUSION

HFRS is a better predictor of length of stay (LOS), ICU stays, and nonhome discharges than readmission and may improve on modified frailty index in predicting LOS. Since ICU stays and nonhome discharges are the main drivers of cost variability in spine surgery, HFRS may be a valuable tool for cost prediction in this specialty.

Recent trends in medicare utilization and reimbursement for lumbar spine fusion and discectomy procedures

BACKGROUND CONTEXT

Understanding the scope of the volume and costs of lumbar fusions and discectomy procedures, as well as identifying significant trends within the Medicare system, may be beneficial in enhancing cost-efficiency and care delivery. However, there is a paucity of studies which analyze recent trends in lumbar fusion volume, utilization, and reimbursements.

PURPOSE

This study seeks to define the costs of lumbar fusions and discectomy procedures and identify trends and variations in volume, utilization, and surgeon and hospital reimbursement rates in the Medicare system between 2012 and 2017.

STUDY DESIGN

Retrospective database study.

PATIENT SAMPLE

Medicare Part A and Part B claims submitted for lumbar spine procedures from 2012 to 2017, as documented in the Centers for Medicare & Medicaid Services Physician and Other Supplier Public Use Files.

OUTCOME MEASURES

Procedure numbers and payments per episode.

METHODS

This cross-sectional study tracked annual Medicare claims and payments to spine surgeons using publicly-available databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates (per 10,000 Medicare beneficiaries), and reimbursement rates, and to examine associations between county-specific and lumbar spine procedure utilization and reimbursements.

RESULTS

A total of 772,532 lumbar spine procedures were performed in the Medicare population from 2012 to 2017, including 634,335 lumbar fusion surgeries and 138,197 primary lumbar discectomy and microdiscectomy single-level surgeries. There was a 26.0% increase in annual lumbar fusion procedure volume during the study period, with a compound annual growth rate (CAGR) of 4.7%. Lumbar discectomy/microdiscectomy experienced a 23.5% decrease in annual procedure volume (CAGR, -5.2%). Mean Medicare surgeon reimbursements for lumbar fusions nominally decreased by 3.7% from $767 in 2012 to $738 in 2017, equivalent to an inflation-adjusted decrease of 11.4% (CAGR, -0.7%). Mean Medicare payments for lumbar discectomy and microdiscectomy procedures nominally increased by 16.3% from $517 in 2012 to $601 in 2017, equivalent to an inflation-adjusted increase of 6.9% (CAGR, 3.1%).

CONCLUSIONS

This present study found the volume and utilization of lumbar fusions have increased since 2012, while lumbar discectomy and microdiscectomy volume and utilization have fallen. Medicare payments to hospitals and surgeons for lumbar fusions have either declined or not kept pace with inflation, and reimbursements for lumbar discectomy and microdiscectomy to hospitals have risen at a disproportionate rate compared to surgeon payments. These trends in Medicare payments, especially seen in decreasing allocation of reimbursements for surgeons, may be the effect of value-based cost reduction measures, especially for high-cost orthopedic and spine surgeries.

The Value of Plastic Surgery Spinal Closures: A Review of 782 Spine Cases

BACKGROUND

The role of the plastic surgeon in wound management after complications from previous spinal surgeries is well established.

PURPOSE

The present study evaluates wound complications after plastic surgeon closure of the primary spinal surgery in a large patient population.

STUDY DESIGN AND SETTING

This is a retrospective review of spine surgery patients undergoing plastic surgeon closure of spine surgeries at a single tertiary care center.

PATIENT SAMPLE

Spine surgery patients included those who were referred for plastic surgeon closure due to (a) concerns about patient healing potential, (b) concerns about difficulty of closure, (c) patient request, or (d) difficulties with closure intraoperatively.

OUTCOME MEASURES

The outcomes are physiologic measures, including intraoperative and postoperative complications, hospital length of stay, and 30-day readmissions and reoperations.

METHODS

Outcomes in this sample were compared with previously published outcomes using 2-sample z tests. The authors have no conflicts of interest.

RESULTS

Nine hundred twenty-eight surgeries were reviewed, of which 782 were included. Fourteen patients (1.8%) required readmission with 30 days. This compares favorably to a pooled analysis of 488,049 patients, in which the 30-day readmission rate was found to be 5.5% (z = 4.5, P < 0.0001). Seven patients (0.89%) had wound infection and 3 (0.38%) wound dehiscence postoperatively, compared with a study of 22,430 patients in the American College of Surgeons National Surgery Quality Improvement Program database, which had an infection incidence of 2.2% (z = 2.5, P = 0.0132) and 0.3% dehiscence rate (z = 0.4, P = 0.6889). The combined incidence of wound complications in the present sample was 1.27%, which is less than the combined incidence of wound complications in the population of 22,430 patients (z = 2.2, P = 0.029).

CONCLUSIONS

Thirty-day readmissions and wound complications are intensely scrutinized quality metrics that may lead to reduced reimbursements and other penalties for hospitals. Plastic surgeon closure of index spinal cases decreases these adverse outcomes. Further research must be conducted to determine whether the increased cost of plastic surgeon involvement in these cases is offset by the savings represented by fewer readmissions and complications.

Hospital and Surgeon Medicare Reimbursement Trends for Total Joint Arthroplasty

BACKGROUND

Over 1 million total joint arthroplasties (TJAs) are performed every year in the United States, creating Medicare cost concerns for policy makers. The purpose of this study is to evaluate recent trends in Medicare utilization and reimbursements to hospitals/surgeons for TJAs between 2012 and 2017.

METHODS

We tracked annual Medicare claims and payments to TJA surgeons using publicly available Medicare databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization (per 10,000 Medicare beneficiaries), and reimbursement rates and to examine associations between county-specific variables and TJA utilization and reimbursements.

RESULTS

Between 2012 and 2017, there was an 18.9% increase in annual primary TJA volume (357,500 cases in 2012 to 425,028 cases in 2017) and a 2.0% increase in annual primary TJA per capita utilization (73.4 cases per 10,000 Medicare beneficiaries in 2012 to 74.8 in 2017). The Midwest and the South had higher utilization rates compared with the Northeast and West (P < .001). Utilization rates for primary TJA procedures also had a significant negative association with the poverty rate (P < .001). Medicare Part B payments to surgeons fell by 7.5%, equivalent to a 14.9% inflation-adjusted decline, whereas hospital reimbursements and charges increased by 0.3% and 18.6%, respectively, during the study period.

CONCLUSIONS

Despite increasing TJA volume and utilization, surgeon reimbursements have continued to decline, whereas hospital payments and hospital charges have increased significantly more than surgeon charges. Cost containment efforts will need to address other expenditures such as hospital costs and implant costs to better align financial risks and incentives for TJA surgeons.

Later Surgical Start Time Is Associated With Longer Length of Stay and Higher Cost in Cervical Spine Surgery

STUDY DESIGN

Retrospective study of a surgical cohort from a single, large academic institution.

OBJECTIVE

The aim of this study was to investigate associations between surgical start time, length of stay, cost, perioperative outcomes, and readmission.

SUMMARY OF BACKGROUND DATA

One retrospective study with a smaller cohort investigated associations between surgical start time and outcomes in spine surgery and found that early start times were correlated with shorter length of stay. No examinations of perioperative outcomes or cost have been performed.

METHODS

All patients undergoing anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) were queried from a single institution from January 1, 2008 to November 30, 2016. Patients undergoing surgery that started between 12:00 AM and 6:00 AM were excluded due to their likely emergent nature. Cases starting before and after 2:00 PM were compared on the basis of length of stay and cost as the primary outcomes using multivariable logistic regression.

RESULT

The patients undergoing ACDF and PCDF were both similar on the basis of comorbidity burden, preoperative diagnosis, and number of segments fused. The patients undergoing ACDF starting after 2 PM had longer LOS values (adjusted difference of 0.65 days; 95% confidence interval [CI]: 0.28-1.03; P = 0.0006) and higher costs of hospitalization (adjusted difference of $1177; 95% CI: $549-$1806; P = 0.0002). Patients undergoing PCDF starting after 2 PM also had longer LOS values (adjusted difference of 1.19 days; 95% CI: 0.46-1.91; P = 0.001) and higher costs of hospitalization (adjusted difference of $2305; 95% CI: $826-$3785; P = 0.002).

CONCLUSION

Later surgical start time is associated with longer LOS and higher cost. These findings should be further confirmed in the spine surgical literature to investigate surgical start time as a potential cost-saving measure.

LEVEL OF EVIDENCE

3.

Correlation of perioperative risk scores with hospital costs in neurosurgical patients

OBJECTIVE

The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) online surgical risk calculator uses inherent patient characteristics to provide predictive risk scores for adverse postoperative events. The purpose of this study was to determine if predicted perioperative risk scores correlate with actual hospital costs.

METHODS

A single-center retrospective review of 1005 neurosurgical patients treated between September 1, 2011, and December 31, 2014, was performed. Individual patient characteristics were entered into the NSQIP calculator. Predicted risk scores were compared with actual in-hospital costs obtained from a billing database. Correlational statistics were used to determine if patients with higher risk scores were associated with increased in-hospital costs.

RESULTS

The Pearson correlation coefficient (R) was used to assess the correlation between 11 types of predicted complication risk scores and 5 types of encounter costs from 1005 health encounters involving neurosurgical procedures. Risk scores in categories such as any complication, serious complication, pneumonia, cardiac complication, surgical site infection, urinary tract infection, venous thromboembolism, renal failure, return to operating room, death, and discharge to nursing home or rehabilitation facility were obtained. Patients with higher predicted risk scores in all measures except surgical site infection were found to have a statistically significant association with increased actual in-hospital costs (p < 0.0005).

CONCLUSIONS

Previous work has demonstrated that the ACS NSQIP surgical risk calculator can accurately predict mortality after neurosurgery but is poorly predictive of other potential adverse events and clinical outcomes. However, this study demonstrates that predicted high-risk patients identified by the ACS NSQIP surgical risk calculator have a statistically significant moderate correlation to increased actual in-hospital costs. The NSQIP calculator may not accurately predict the occurrence of surgical complications (as demonstrated previously), but future iterations of the ACS universal risk calculator may be effective in predicting actual in-hospital costs, which could be advantageous in the current value-based healthcare environment.

American Society of Anesthesiologists' Status Association With Cost and Length of Stay in Lumbar Laminectomy and Fusion: Results From an Institutional Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The objective of this study was to characterize the costs associated with American Society of Anesthesiologists (ASA) class, and to determine the extent to which ASA status is a predictor of increased cost and LOS following lumbar laminectomy and fusion (LLF).

SUMMARY OF BACKGROUND DATA

Spinal fusion accounts for the highest hospital costs of any surgical procedure performed in the United States, and ASA (American Society of Anesthesiologists) status is a known risk factor for cost and length of stay (LOS) in the orthopedic literature. There is a paucity of literature that directly addresses the influence of ASA status on cost and LOS following LLF.

METHODS

This is a retrospective cohort study of an institutional database of patients undergoing single-level LLF at an academic tertiary care facility from 2006 to 2016. Univariate comparisons were made using χ tests for categorical variables and t tests for continuous variables. Multivariate linear regression was utilized to estimate regression coefficients, and to determine whether ASA status is an independent risk factor for cost and LOS.

RESULTS

A total of 1849 patients met inclusion criteria. For every one-point increase in ASA score, intensive care unit (ICU) LOS increased by 0.518 days (P < 0.001), and hospital length of stay increased by 1.93 days (P < 0.001). For every one-point increase in ASA score, direct cost increased by $7474.62 (P < 0.001).

CONCLUSION

ASA status is a predictor of hospital LOS, ICU LOS, and direct cost. Consideration of the ways in which ASA status contributes to increased cost and prolonged LOS can allow for more accurate reimbursement adjustment and more precise targeting of efficiency and cost effectiveness initiatives.

LEVEL OF EVIDENCE

3.

Can a machine learning model accurately predict patient resource utilization following lumbar spinal fusion?

BACKGROUND CONTEXT

With the increasing emphasis on value-based healthcare in Centers for Medicare and Medicaid Services reimbursement structures, bundled payment models have been adopted for many orthopedic procedures. Immense variability of patients across hospitals and providers makes these models potentially less viable in spine surgery. Machine-learning models have been shown reliable at predicting patient-specific outcomes following lumbar spine surgery and could, therefore, be applied to developing stratified bundled payment schemes.

PURPOSE

(1) Can a Naïve Bayes machine-learning model accurately predict inpatient payments, length of stay (LOS), and discharge disposition, following dorsal and lumbar fusion? (2) Can such a model then be used to develop a risk-stratified payment scheme?

STUDY DESIGN

A Naïve Bayes machine-learning model was constructed using an administrative database.

PATIENT SAMPLE

Patients undergoing dorsal and lumbar fusion for nondeformity indications from 2009 through 2016 were included. Preoperative inputs included age group, gender, ethnicity, race, type of admission, All Patients Refined (APR) risk of mortality, APR severity of illness, and Clinical Classifications Software diagnosis code.

OUTCOME MEASURES

Predicted resource utilization outcomes included LOS, discharge disposition, and total inpatient payments. Model validation was addressed via reliability, model output quality, and decision speed, based on application of training and validation sets. Risk-stratified payment models were developed according to APR risk of mortality and severity of illness.

RESULTS

A Naïve Bayes machine-learning algorithm with adaptive boosting demonstrated high reliability and area under the receiver-operating characteristics curve of 0.880, 0.941, and 0.906 for cost, LOS, and discharge disposition, respectively. Patients with increased risk of mortality or severity of illness incurred costs resulting in greater inpatient payments in a patient-specific tiered bundled payment, reflecting increased risk on institutions caring for these patients. We found that a large range in expected payments due to individuals' preoperative comorbidities indicating an individualized risk-based model is warranted.

CONCLUSIONS

A Naïve Bayes machine-learning model was shown to have good-to-excellent reliability and responsiveness for cost, LOS, and discharge disposition. Based on APR risk of mortality and APR severity of illness, there was a significant difference in episode costs from lowest to highest risk strata. After using normalized model error to develop a risk-adjusted proposed payment plan, it was found that institutions incur significantly more financial risk in flat bundled payment models for patients with higher rates of comorbidities.

Plastic Surgeon Closure of Index Spinal Cases: A Single-Institution Review of 928 Cases

PURPOSE

The role of the plastic surgeon in wound management following complications from prior spinal surgeries is well established. The present study evaluates wound complications following plastic surgeon closure of the primary spinal surgery in a large patient population.

METHODS

Spinal surgeries closed by a single plastic surgeon at a large academic hospital were reviewed. Descriptive statistics were applied and outcomes in this sample were compared with previously published outcomes using 2-sample z tests.

RESULTS

Nine hundred twenty-eight surgeries were reviewed, of which 782 were included. Seven hundred fifteen operations were for degenerative conditions of the spine, 22 for trauma, 30 for neoplasms, and 14 for congenital conditions. Four hundred twenty-one were lumbosacral procedures (53.8%) and 361 (46.2%) cervical. Fourteen patients (1.8%) required readmission with 30 days. This compares favorably to a pooled analysis of 488049 patients, in which the 30-day readmission rate was found to be 5.5% (z=4.5, P<0.0001). Seven patients (0.89%) had wound infection and 3 (0.38%) wound dehiscence postoperatively, compared with a study of 22,430 patients in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database who had an infection incidence of 2.2% (z=2.5, P=0.0132) and 0.3% dehiscence rate (z=0.4, P=0.6889). The combined incidence of wound complications in the present sample, 1.27%, was less than the combined incidence of wound complications in the population of 22,430 patients (z=2.2, P=0.029).

CONCLUSIONS

Thirty-day readmissions and wound complications are intensely scrutinized quality metrics that may lead to reduced reimbursements and other penalties for hospitals. Plastic surgeon closure of index spinal cases decreases these adverse outcomes. Further research must be done to determine whether the increased cost of plastic surgeon involvement in these cases is offset by the savings represented by fewer readmissions and complications.

Does the Day of the Week Affect Length of Stay and Hospital Charges Following Anterior Cervical Discectomy and Fusion?

Background

To reduce the economic impact of excessive costs, risk factors for increased length of stay (LOS) must be identified. Previous literature has demonstrated that surgeries later in the week can affect the LOS and costs following joint arthroplasty. However, few investigations regarding the day of surgery have been performed in the spine literature. The present study attempts to identify the association between day of surgery on LOS and hospital charges following anterior cervical discectomy and fusion (ACDF) procedures.

Methods

A prospectively maintained surgical database of primary, level 1-2 ACDF patients between 2008 and 2015 was retrospectively reviewed. Patients were stratified by surgery day: early week (Tuesday) or late week (Friday) ACDF. Differences in patient demographics and preoperative characteristics were compared between cohorts using chi-square analysis or Student t test for categorical and continuous variables, respectively. Direct hospital costs were obtained using hospital charges for each procedure and subsequent care prior to discharge. Associations between date of surgery and costs were assessed using multivariate linear regression controlled for.

Results

Two hundred and ninety-five patients were included in the analysis. One hundred and fifty-three patients underwent early week ACDF, and 142 underwent late week ACDF. Surgery day cohorts reported similar baseline characteristics. There were no differences in operative characteristics or hospital LOS between cohorts. Additionally, no differences in total or subcategorical hospital costs were identified between surgery day cohorts.

Conclusions

Patients undergoing ACDF later in the week exhibit similar LOS and hospital costs compared to those undergoing ACDF early in the week. These results suggest that outpatient procedures with short postoperative stays are likely not affected by the changes in hospital work efficiency that occur during the transition to the weekend. As such, hospitals should not restrict outpatient procedures to specific days of the week.

Level of Evidence

3.

Patient Demographic and Surgical Factors that Affect Completion of Patient-Reported Outcomes 90 Days and 1 Year After Spine Surgery: Analysis from the Michigan Spine Surgery Improvement Collaborative (MSSIC)

BACKGROUND

The Michigan Spine Surgery Improvement Collaborative is a statewide multicenter quality improvement registry. Because missing data can affect registry results, we used MSSIC to find demographic and surgical characteristics that affect the completion of patient-reported outcomes (PROs) at 90 days and 1 year.

METHODS

A total of 24,404 patients who had lumbar surgery (17,813 patients) or cervical surgery (6591 patients) were included. Multivariate logistic regression models of patient disease were constructed to identify risk factors for failure to complete scheduled PRO surveys.

RESULTS

Patients ≥65 years old and female patients were both more likely to respond at 90 days and 1 year. Increasing education was associated with greater response rate at 90 days and 1 year. Whites and African Americans had no differences in response rates. Calling provided the highest response rate at 90 days and 1 year. For cervical spine patients, only discharge to rehabilitation increased completion rates, at 90 days but not 1 year. For lumbar spine patients, spondylolisthesis or stenosis (vs. herniated disc) had a greater response rate at 1 year. Patients with leg (vs. back) pain had a greater response only at 1 year. Patients with multilevel surgery had an increased response at 1 year. Patients who underwent fusion were more likely to respond at 90 days, but not 1 year. Discharge to rehabilitation increased response at 90 days and 1 year.

CONCLUSIONS

A multivariate analysis from a multicenter prospective database identified surgical factors that affect PRO follow-up, up to 1 year. This information can be helpful for imputing missing PRO data and could be used to strengthen data derived from large prospective databases.

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.

Perioperative Protocol for Elective Spine Surgery Is Associated With Reduced Length of Stay and Complications

INTRODUCTION

Healthcare reform places emphasis on maximizing the value of care.

METHODS

A prospective registry was used to analyze outcomes before (1,596 patients) and after (151 patients) implementation of standardized, evidence-based order sets for six high-impact dimensions of perioperative care for all patients who underwent elective surgery for degenerative spine disease after July 1, 2015.

RESULTS

Apart from symptom duration, chronic obstructive pulmonary disease prevalence, estimated blood loss, and baseline Oswestry Disability Index, no significant differences existed between pre- and post-protocol cohorts. No differences in readmissions, discharge status, or 3-month patient-reported outcomes were seen. Multivariate regression analyses demonstrated reduced length of stay (P = 0.013) and odds of 90-day complications (P = 0.009) for postprotocol patients.

CONCLUSION

Length of stay and 90-day complications for elective spine surgery improved after implementation of an evidence-based perioperative protocol. Standardization efforts can improve quality and reduce costs, thereby improving the value of spine care.

LEVEL OF EVIDENCE

Level III (retrospective review of prospectively collected data).

Preparing for Bundled Payments in Cervical Spine Surgery: Do We Understand the Influence of Patient, Hospital, and Procedural Factors on the Cost and Length of Stay?

STUDY DESIGN

Retrospective, observational study.

OBJECTIVE

To examine the influence of patient, hospital, and procedural characteristics on hospital costs and length hospital of stay (LOS).

SUMMARY OF BACKGROUND DATA

Successful bundled payment agreements require management of financial risk. Participating institutions must understand potential cost input before entering into these episodes-of-care payment contracts. Elective anterior cervical discectomy and fusion (ACDF) has become a popular target for early bundles given its frequency and predictability.

METHODS

A national discharge database was queried to identify adult patients undergoing elective ACDF. Using generalized linear models, the impact of each patient, hospital, and procedures characteristic on hospitalization costs and the LOS was estimated.

RESULTS

In 2011, 134,088 patients underwent ACDF in the United States. Of these 31.6% had no comorbidities, whereas 18.7% had three or more. The most common conditions included hypertension (44.4%), renal disease (15.9%), and depression (14.7%). Mean hospital costs after ACDF was $18,622 and mean hospital LOS was 1.7 days. With incremental comorbidities, both hospital costs and LOS increased. Both marginal costs and LOS rose with inpatient death (+$17,181, +2.0 days), patients with recent weight loss (+$8351, +1.24 days), metastatic cancer (+$6129 +0.80 days), electrolyte disturbances (+$4175 +0.8 days), pulmonary-circulatory disorders (+$4065, +0.6 days), and coagulopathies (+$3467, +0.58 days). Costs and LOS were highest with the following procedures: addition of a posterior fusion/instrumentation ($+11,189, +0.9 days), revision anterior surgery (+$3465, +0.3 days), and fusion of more than three levels (+$3251, +0.2 days). Patients treated in the West had the highest costs (+$9300, +0.3 days). All P values were less than 0.05.

CONCLUSION

Hospital costs and LOS after ACDF rise with increasing patient comorbidities. Stakeholders entering into bundled payments should be aware of that certain patient, hospital, and procedure characteristics will consume greater resources.

LEVEL OF EVIDENCE

3.

Determinants and Variations of Hospital Costs in Patients With Lumbar Radiculopathy Hospitalized for Spinal Surgery

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to determine hospital costs related to surgery for lumbar radiculopathy and identify determinants of intramural costs based on minimal hospital and claims data.

SUMMARY OF BACKGROUND DATA

Costs related to the initial hospitalization of patients undergoing surgery for lumbar radiculopathy make up the major part of direct health care expenditure in this population. Identifying factors influencing intramural costs can be beneficial for health care policy makers, and clinicians working with patients with lumbar radiculopathy.

METHODS

The following data were collected from the University Hospital Brussels data warehouse for all patients undergoing surgery for lumbar radiculopathy in 2016 (n = 141): age, sex, primary diagnosis, secondary diagnoses, type of surgery, severity of illness (SOI), admission and discharge date, type of hospital admission, and all claims incurred for the particular hospital stay. Descriptive statistics for total hospital costs were performed. Univariate analyses were executed to explore associations between hospital costs and all other variables. Those showing a significant association (P < 0.05) were included in the multivariate general linear model analysis.

RESULTS

Mean total hospital costs were &OV0556; 5016 ± 188 per patient. Costs related to the actual residence (i.e., "hotel costs") comprised 53% of the total hospital costs, whereas 18% of the costs were claimed for the surgical procedure. Patients with moderate/major SOI had 44% higher hospital costs than minor SOI (P = 0.01). Presence of preadmission comorbidities incurred 46% higher costs (P = 0.03). Emergency procedures led to 72% higher costs than elective surgery (P < 0.001). Patients receiving spinal fusion had 211% higher hospital costs than patients not receiving this intervention (P < 0.001).

CONCLUSION

Hospital costs in patients receiving surgery for lumbar radiculopathy are influenced by SOI, the presence of preadmission comorbidities, type of hospital admission (emergency vs. elective), and type of surgical procedure.

LEVEL OF EVIDENCE

3.

Fibromyalgia as a Predictor of Increased Postoperative Complications, Readmission Rates, and Hospital Costs in Patients Undergoing Posterior Lumbar Spine Fusion

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim of this study was to identify whether a concomitant diagnosis of fibromyalgia (FM) influences postoperative complications, readmission rates or cost following primary 1 to 2 level lumbar fusions in an elective setting.

SUMMARY OF BACKGROUND DATA

Patients with FM often are limited by chronic lower back pain, many of whom will seek operative treatment. No previous study has evaluated whether patients with a concomitant diagnosis of FM have more complications following spine surgery.

METHODS

Medicare data (2005-2014) from a national database was queried for patients who underwent primary 1 to 2 level posterolateral lumbar spine fusion for degenerative lumbar pathology. Thirty- and 90-day postoperative complication rates, readmission rates, and treatment costs were queried. To reduce confounding, FM patients were matched with a control cohort of non-FM patients using patient demographics, treatment modality, and comorbid conditions, and then analyzed by multivariable logistic regression.

RESULTS

Within the first 30-day postoperative, acute post hemorrhagic anemia (odds ratio [OR]: 2.58; P < 0.001) and readmission rates were significantly higher in FM patients compared to controls. There was no significant difference in wound related complications within first 30-days (0.19% vs. 0.23%; P = 0.520) or with length of stay (3.60 vs. 3.53 days; P = 0.08). Within 90-day postoperative, FM patients had higher rates of pneumonia (OR: 3.73; P < 0.001) and incurred 5.31% more in hospital charges reimbursed compared to the control cohort.

CONCLUSION

Primary 1 to 2 level lumbar fusions performed on FM patients have higher rates of postoperative anemia, pneumonia, cost of care, and readmission compared to match controls. FM patients and surgeons should be aware of these increased risks in an effort to control hospital costs and potential complications.

LEVEL OF EVIDENCE

3.

Risk Factors for a Long Hospital Stay Following Minimally Invasive Lumbar Discectomy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of the study was to determine risk factors for discharge after postoperative day (POD) 0 in patients undergoing 1-level minimally invasive lumbar discectomy (MIS LD).

SUMMARY OF BACKGROUND DATA

MIS LD has proven to be an effective treatment modality for low back pain and radiculopathy associated with intervertebral disc herniations. With increasing focus on cost reduction and value-based care, minimization of postoperative length of stay has become an important topic for physicians and hospital administrators.

METHODS

A prospectively maintained surgical database of patients who underwent 1-level MIS LD by a single surgeon from 2011 to 2016 was reviewed. Long length of stay was defined as discharge after POD 0. Bivariate and stepwise multivariate Poisson regression with robust error variance was used to determine risk factors for discharge after POD 0. Variables analyzed included patient demographics, comorbidities, operative characteristics, preoperative pain scores, postoperative inpatient pain scores, and postoperative narcotics consumption.

RESULTS

A total of 176 patients were included; 9.7% of included patients were discharged on POD 1 or later. On bivariate analysis, diabetic status (57.1% vs. 7.7%; relative risk [RR]=7.43; P<0.01) and narcotic consumption <6.00 oral morphine equivalents/h (13.1% vs. 1.2%; RR=11.11; P=0.019) were associated with a prolonged length of stay. On stepwise multivariate analysis, diabetic status (RR=10.5; 95% confidence interval, 3.60-30.98; P<0.001) was found to be independently associated with a prolonged length of stay after MIS LD.

CONCLUSIONS

The results indicate that diabetic status is an independent risk factor for increased LOS following single-level MIS LD. Delayed hospital discharge can lead to increased costs, increased risk of complications, and decreased patient satisfaction. Thus, providers can use this information to better counsel diabetic patients and monitor them more closely following MIS LD. Additional work must be done to better understand risk factors for increased length of stay following MIS LD in procedure-specific populations.

LEVEL OF EVIDENCE

Level II.