ARID1A orchestrates SWI/SNF-mediated sequential binding of transcription factors with ARID1A loss driving pre-memory B cell fate and lymphomagenesis.

ARID1A, a subunit of the canonical BAF nucleosome remodeling complex, is commonly mutated in lymphomas. We show that ARID1A orchestrates B cell fate during the germinal center (GC) response, facilitating cooperative and sequential binding of PU.1 and NF-kB at crucial genes for cytokine and CD40 signaling. The absence of ARID1A tilts GC cell fate toward immature IgM+CD80-PD-L2- memory B cells, known for their potential to re-enter new GCs. When combined with BCL2 oncogene, ARID1A haploinsufficiency hastens the progression of aggressive follicular lymphomas (FLs) in mice. Patients with FL with ARID1A-inactivating mutations preferentially display an immature memory B cell-like state with increased transformation risk to aggressive disease. These observations offer mechanistic understanding into the emergence of both indolent and aggressive ARID1A-mutant lymphomas through the formation of immature memory-like clonal precursors. Lastly, we demonstrate that ARID1A mutation induces synthetic lethality to SMARCA2/4 inhibition, paving the way for potential precision therapy for high-risk patients.

Association Between Intravenous to Oral Opioid Transition Time and Length of Hospital Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

BACKGROUND: Transitioning from intravenous (IV) to oral opioids after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) is necessary during the postoperative course. However, few studies have assessed the effects of longer transition times on hospital length of stay (LOS). This study investigated the impact of longer IV to oral opioid transition times on LOS after PSF for AIS. METHODS: The medical records of 129 adolescents (10-18 years old) with AIS undergoing multilevel PSF at a major academic institution from 2013 to 2020 were reviewed. Patients were categorized by IV to oral opioid transition time: normal (≤2 days) vs prolonged (≥3 days). Patient demographics, comorbidities, deformity characteristics, intraoperative variables, postoperative complications, and LOS were assessed. Multivariate analyses were used to determine odds ratios for risk-adjusted extended LOS. RESULTS: Of the 129 study patients, 29.5% (n = 38) had prolonged IV to oral transitions. Demographics and comorbidities were similar between the cohorts. The major curve degree (P = 0.762) and median (interquartile range) levels fused (P = 0.447) were similar between cohorts, but procedure time was significantly longer in the prolonged cohort (normal: 6.6 ± 1.2 hours vs prolonged: 7.2 ± 1.3 hours, P = 0.009). Postoperative complication rates were similar between the cohorts. Patients with prolonged transitions had significantly longer LOS (normal: 4.6 ± 1.3 days vs prolonged: 5.1 ± 0.8 days, P < 0.001) but similar discharge disposition (P = 0.722) and 30-day readmission rates (P > 0.99). On univariate analysis, transition time was significantly associated with extended LOS (OR: 2.0, 95% CI [0.9, 4.6], P = 0.014), but this assocation was not significant on multivariate analysis (adjusted OR: 2.1, 95% CI [1.3, 4.8], P = 0.062). CONCLUSIONS: Longer postoperative IV to oral opioid transitions after PSF for AIS may have implications for hospital LOS.

Prevalence and Influence of Frailty on Hospital Outcomes After Surgical Resection of Spinal Meningiomas.

OBJECTIVE: Frailty has been shown to affect patient outcomes after medical and surgical interventions. The Hospital Frailty Risk Score (HFRS) is a growing metric used to assess patient frailty using International Classification of Diseases, Tenth Revision codes. The goal of this study was to investigate the impact of frailty, assessed by HFRS, on health care resource utilization and outcomes in patients undergoing surgery for spinal meningiomas. METHODS: A retrospective cohort study was performed using the 2016-2019 National Inpatient Sample database. Adult patients with benign or malignant spinal meningiomas, identified using International Classification of Diseases, Tenth Revision, Clinical Modification codes, were stratified by HFRS: low frailty (HFRS <5) and intermediate-high frailty (HFRS ≥5). Patient demographics, hospital characteristics, comorbidities, procedural variables, adverse events, length of stay (LOS), discharge disposition, and cost of admission were assessed. Multivariate regression analysis was used to identify predictors of increased LOS, discharge disposition, and cost. RESULTS: Of the 3345 patients, 530 (15.8%) had intermediate-high frailty. The intermediate-high cohort was significantly older (P < 0.001). More patients in the intermediate-high cohort had ≥3 comorbidities (P < 0.001). In addition, a greater proportion of patients in the intermediate-high cohort experienced ≥1 perioperative adverse events (P < 0.001). Intermediate-high patients experienced greater mean LOS (P < 0.001) and accrued greater costs (P < 0.001). A greater proportion of intermediate-high patients had nonroutine discharges (P < 0.001). On multivariate analysis, increased HFRS (≥5) was independently associated with extended LOS (adjusted odds ratio [aOR], 3.04; P < 0.001), nonroutine discharge (aOR, 1.98; P = 0.006), and increased costs (aOR, 2.39; P = 0.004). CONCLUSIONS: Frailty may be associated with increased health care resource utilization in patients undergoing surgery for spinal meningiomas.

A current review of spinal meningiomas: epidemiology, clinical presentation and management.

PURPOSE: To provide an up-to-date review of the epidemiology, histopathology, molecular biology, and etiology of spinal meningiomas, as well as discuss the clinical presentation, clinical evaluation, and most recent treatment recommendations for these lesions. METHODS: PubMed and Google Scholar search was performed for studies related to meningiomas of the spine. The terms "meningioma," "spinal meningioma," "spine meningioma," "meningioma of the spine," "benign spinal tumors," and "benign spine tumors," were used to identify relevant studies. All studies, including primary data papers, meta-analyses, systematic reviews, general reviews, case reports, and clinical trials were considered for review. RESULTS: Eighty-four studies were identified in the review. There were 22 studies discussing adverse postoperative outcomes, 21 studies discussing tumor genetics, 19 studies discussing epidemiology and current literature, 9 studies discussing radiation modalities and impact on subsequent tumor development, 5 studies on characteristic imaging findings, 5 studies discussing hormone use/receptor status on tumor development, 2 discussing operative techniques and 1 discussing tumor identification. CONCLUSION: Investigations into spinal meningiomas generally lag behind that of intracranial meningiomas. Recent advancements in the molecular profiling of spinal meningiomas has expanded our understanding of these tumors, increasing our appreciation for their heterogeneity. Continued investigation into the defining characteristics of different spinal meningiomas will aid in treatment planning and prognostication.

Hospital Frailty Risk Score and Healthcare Resource Utilization After Surgery for Primary Spinal Intradural/Cord Tumors.

OBJECTIVE: The Hospital Frailty Risk Score (HFRS) is a metric that measures frailty among patients in large national datasets using ICD-10 codes. While other metrics have been utilized to demonstrate the association between frailty and poor outcomes in spine oncology, none have examined the HFRS. The aim of this study was to investigate the impact of frailty using the HFRS on complications, length of stay, cost of admission, and discharge disposition in patients undergoing surgery for primary tumors of the spinal cord and meninges. METHODS: A retrospective cohort study was performed using the Nationwide Inpatient Sample database from 2016 to 2018. Adult patients undergoing surgery for primary tumors of the spinal cord and meninges were identified using ICD-10-CM codes. Patients were categorized into 2 cohorts based on HFRS score: Non-Frail (HFRS<5) and Frail (HFRS≥5). Patient characteristics, treatment, perioperative complications, LOS, discharge disposition, and cost of admission were assessed. RESULTS: Of the 5955 patients identified, 1260 (21.2%) were Frail. On average, the Frail cohort was nearly 8 years older (P < .001) and experienced more postoperative complications (P = .001). The Frail cohort experienced longer LOS (P < .001), a higher rate of non-routine discharge (P = .001), and a greater mean cost of admission (P < .001). Frailty was found to be an independent predictor of extended LOS (P < .001) and non-routine discharge (P < .001). CONCLUSION: Our study is the first to use the HFRS to assess the impact of frailty on patients with primary spinal tumors. We found that frailty was associated with prolonged LOS, non-routine discharge, and increased hospital costs.

Higher Hospital Frailty Risk Score is associated with increased complications and healthcare resource utilization after endovascular treatment of ruptured intracranial aneurysms.

AIM: To use the Hospital Frailty Risk Score (HFRS) to investigate the impact of frailty on complication rates and healthcare resource utilization in patients who underwent endovascular treatment of ruptured intracranial aneurysms (IAs). METHODS: A retrospective cohort study was performed using the 2016-2019 National Inpatient Sample database. All adult patients (≥18 years) undergoing endovascular treatment for IAs after subarachnoid hemorrhage were identified using ICD-10-CM codes. Patients were categorized into frailty cohorts: low (HFRS <5), intermediate (HFRS 5-15) and high (HFRS >15). Patient demographics, adverse events, length of stay (LOS), discharge disposition, and total cost of admission were assessed. Multivariate logistic regression analysis was used to identify independent predictors of prolonged LOS, increased cost, and non-routine discharge. RESULTS: Of the 33 840 patients identified, 7940 (23.5%) were found to be low, 20 075 (59.3%) intermediate and 5825 (17.2%) high frailty by HFRS criteria. The rate of encountering any adverse event was significantly greater in the higher frailty cohorts (low: 59.9%; intermediate: 92.4%; high: 99.2%, p<0.001). There was a stepwise increase in mean LOS (low: 11.7±8.2 days; intermediate: 18.7±14.1 days; high: 26.6±20.1 days, p<0.001), mean total hospital cost (low: $62 888±37 757; intermediate: $99 670±63 446; high: $134 937±80 331, p<0.001), and non-routine discharge (low: 17.3%; intermediate: 44.4%; high: 69.4%, p<0.001) with increasing frailty. On multivariate regression analysis, a similar stepwise impact was found in prolonged LOS (intermediate: OR 2.38, p<0.001; high: OR 4.49, p<0.001)], total hospital cost (intermediate: OR 2.15, p<0.001; high: OR 3.62, p<0.001), and non-routine discharge (intermediate: OR 2.13, p<0.001; high: OR 4.17, p<0.001). CONCLUSIONS: Our study found that greater frailty as defined by the HFRS was associated with increased complications, LOS, total costs, and non-routine discharge.

Hospital Frailty Risk Score Predicts Adverse Events and Readmission Following a Ventriculoperitoneal Shunt Surgery for Normal Pressure Hydrocephalus.

OBJECTIVE: The aim of this study was to evaluate the impact of a Hospital Frailty Risk Score (HFRS) on unplanned readmission and health care resource utilization in normal pressure hydrocephalus (NPH) patients undergoing a ventriculoperitoneal (VP) shunt surgery. METHODS: A retrospective cohort study was performed using the 2016-2019 Nationwide Readmission Database. All NPH patients (≥60 years) undergoing a VP shunt surgery were identified using ICD-10-CM diagnostic and procedural codes. Patients were dichotomized into 2 cohorts as follows: Low HFRS (<5) and Intermediate-High HFRS (≥5). A multivariate logistic regression analysis was then used to identify independent predictors of adverse event (AE) and 30- and 90-day readmission. RESULTS: Of 13,262 patients, 4386 (33.1%) had an Intermediate-High HFRS score. A greater proportion of the Intermediate-High HFRS cohort experienced at least one AE (1.9 vs. 22.1, P < 0.001). The Intermediate-High HFRS cohort also had a longer length of stay (2.3 ± 2.4 days vs. 7.0 ± 7.7 days, P < 0.001), higher non-routine discharge rate (19.9% vs. 39.9%, P < 0.001), and greater admission cost ($14,634 ± 5703 vs. $21,749 ± 15,234, P < 0.001). The Intermediate-High HFRS cohort had higher rates of 30- (7.6% vs. 11.0%, P < 0.001) and 90-day (6.8% vs. 8.3%, P < 0.001) readmissions. On a multivariate regression analysis, Intermediate-High HFRS compared to Low HFRS was an independent predictor of any AE (odds ratio, 16.6; 95% confidence interval, [12.9-21.5]; P < 0.001) and 30-day readmission (odds ratio, 1.4; 95% confidence interval, [1.2-1.7]; P < 0.001). CONCLUSIONS: Our study suggests that frailty, as defined by HFRS, is associated with increased resource utilization in NPH patients undergoing VP shunt surgery. Furthermore, HFRS was an independent predictor of adverse events and 30-day hospital readmission.

Geographic variations in health care resource utilization following elective ACDF for cervical spondylotic myelopathy: A national trend analysis.

BACKGROUND: As health care expenditures continue to increase, standardizing health care delivery across geographic regions has been identified as a method to reduce costs. However, few studies have demonstrated how the practice of elective spine surgery varies by geographic location. The aim of this study was to assess the geographic variations in management, complications, and total cost of elective anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). METHODS: The National Inpatient Sample database (2016-2017) was queried using the ICD-10-CM procedural and diagnostic coding systems to identify all adult (≥18 years) patients with a primary diagnosis of CSM undergoing an elective ACDF. Patients were divided into regional cohorts as defined by the U.S. Census Bureau: Northeast, Midwest, South, and West. Weighted patient demographics, Elixhauser comorbidities, perioperative complications, length of stay (LOS), discharge disposition, and total cost of admission were assessed. RESULTS: A total of 17,385 adult patients were identified. While the age (p=0.116) and proportion of female patients (p=0.447) were similar among the cohorts, race (p<0.001) and healthcare coverage (p<0.001) varied significantly. The Northeast had the largest proportion of patients in the 76-100th household income quartile (Northeast: 32.1%; Midwest: 16.9%; South: 15.7%; West: 27.5%, p<0.001). Complication rates were similar between regional cohorts (Northeast: 10.1%; Midwest: 12.2%; South: 10.3%; West: 11.9%, p=0.503), as was LOS (Northeast: 2.2±2.4 days; Midwest: 2.1±2.4 days; South: 2.0±2.5 days; West: 2.1±2.4 days, p=0.678). The West incurred the greatest mean total cost of admission (Northeast: $19,167±10,267; Midwest: $18,903±9,114; South: $18,566±10,152; West: $24,322±15,126, p<0.001). The Northeast had the lowest proportion of patients with a routine discharge (Northeast: 72.0%; Midwest: 84.8%; South: 82.3%; West: 83.3%, p<0.001). The odds ratio for Western hospital region was 3.46 [95% CI: (2.41, 4.96), p<0.001] compared to the Northeast for increased cost. CONCLUSION: Our study suggests that regional variations exist in elective ACDF for CSM, including patient demographics, hospital costs, and nonroutine discharges, while complication rates and LOS were similar between regions.

Differences in Health Care Resource Utilization After Surgery for Metastatic Spinal Column Tumors in Patients with a Concurrent Affective Disorder in the United States.

BACKGROUND: Affective disorders, such as depression and anxiety, are exceedingly common among patients with metastatic cancer. The aim of this study was to investigate the relationship between affective disorders and health care resource utilization in patients undergoing surgery for a spinal column metastasis. METHODS: A retrospective cohort study was performed using the 2016-2018 National Inpatient Sample database. All adult patients (≥18 years) undergoing surgery for a metastatic spinal tumor were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification coding systems. Patients were categorized into 2 cohorts: no affective disorder (No-AD) and affective disorder (AD). Patient demographics, comorbidities, hospital characteristics, intraoperative variables, postoperative adverse events (AEs), length of stay (LOS), discharge disposition, and total cost of hospital admission were assessed. A multivariate logistic regression analysis was used to identify independent predictors of increased cost, nonroutine discharge, and prolonged LOS. RESULTS: Of the 8360 patients identified, 1710 (20.5%) had a diagnosis of AD. Although no difference was observed in the rates of postoperative AEs between the cohorts (P = 0.912), the AD cohort had a significantly longer mean LOS (No-AD, 10.1 ± 8.3 days vs. AD, 11.6 ± 9.8 days; P = 0.012) and greater total cost (No-AD, $53,165 ± 35,512 vs. AD, $59,282 ± 36,917; P = 0.011). No significant differences in nonroutine discharge were observed between the cohorts (P = 0.265). On multivariate regression analysis, having an affective disorder was a significant predictor of increased costs (odds ratio, 1.45; confidence interval, 1.03-2.05; P = 0.034) and nonroutine discharge (odds ratio, 1.40; confidence interval, 1.06-1.85; P = 0.017), but not prolonged LOS (P = 0.067). CONCLUSIONS: Our study found that affective disorders were significantly associated with greater hospital expenditures and nonroutine discharge, but not prolonged LOS, for patients undergoing surgery for spinal metastases.

Ramifications of Postoperative Dysphagia on Health Care Resource Utilization Following Elective Anterior Cervical Discectomy and Interbody Fusion for Cervical Spondylotic Myelopathy.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: The aim of this study was to investigate patient risk factors and health care resource utilization associated with postoperative dysphagia following elective anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: There is a paucity of data on factors predisposing patients to dysphagia and the burden this complication has on health care resource utilization following ACDF. METHODS: A retrospective cohort study was performed using the Nationwide Inpatient Sample (NIS) database from 2016 to 2017. All adult (above 18 y old) patients undergoing ACDF for cervical spondylotic myelopathy were identified using the ICD-10-CM diagnosis and procedural coding system. Patients were then categorized by whether they had a recorded postoperative dysphagia or no dysphagia. Weighted patient demographics, comorbidities, perioperative complications, length of hospital stay (LOS), discharge disposition, and total cost of admission were assessed. A multivariate stepwise logistic regression was used to determine both the odds ratio for risk-adjusted postoperative dysphagia as well as extended LOS. RESULTS: A total of 17,385 patients were identified, of which 1400 (8.1%) experienced postoperative dysphagia. Compared with the No-Dysphagia cohort, the Dysphagia cohort had a greater proportion of patients experiencing a complication (P=0.004), including 1 complication (No-Dysphagia: 2.9% vs. Dysphagia: 6.8%), and >1 complication (No-Dysphagia: 0.3% vs. Dysphagia: 0.4%). The Dysphagia cohort experienced significantly longer hospital stays (No-Dysphagia: 1.9±2.1 d vs. Dysphagia: 4.2±4.3 d, P<0.001), higher total cost of admission (No-Dysphagia: $19,441±10,495 vs. Dysphagia: $25,529±18,641, P<0.001), and increased rates of nonroutine discharge (No-Dysphagia: 16.5% vs. Dysphagia: 34.3%, P<0.001). Postoperative dysphagia was found to be a significant independent risk factor for extended LOS on multivariate analysis, with an odds ratio of 5.37 (95% confidence interval: 4.09, 7.05, P<0.001). CONCLUSION: Patients experiencing postoperative dysphagia were found to have significantly longer hospital LOS, higher total cost of admission, and increased nonroutine discharge when compared with the patients who did not. LEVEL OF EVIDENCE: Level III.

Impact of race on outcomes and healthcare utilization following spinal fusion for adolescent idiopathic scoliosis.

OBJECTIVES: Racial disparities in spine surgery have been shown to impact surgical management and postoperative complications. However, for adolescent patients with idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF), the influence of race on postoperative outcomes remains unclear. The aim of the study was to investigate the differences in baseline patient demographics, inpatient management, and postoperative complications for adolescents with AIS undergoing elective, posterior spinal surgery (≥ 4 levels). PATIENTS AND METHODS: The Kids' Inpatient Database year 2012 was queried. Adolescent patients (age 10-17 years old) with AIS undergoing elective, PSF (≥ 4 levels) were selected using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Patients were divided into 4 cohorts: Black, White, Hispanic, and Other. Patient demographics, comorbidities, complications, length of hospital stay (LOS), discharge disposition and total cost were recorded. The primary outcome was the rate of intraoperative and postoperative complications and resource utilization after elective PSF intervention. RESULTS: Patient demographics significantly differed between the four cohorts. While age was similar (p = 0.288), the White cohort had a greater proportion of female patients (White: 79.0%; Black: 72.1%; Hispanic: 78.2%; Other: 75.9%, p = 0.006), and the Black cohort had the largest proportion of patients in the 0-25th income quartile (White: 16.1%; Black: 43.3%; Hispanic: 28.0%; Other: 15.3%, p < 0.001). There were significant differences in hospital region (p < 0.001) and bed size (p < 0.001) between the cohorts, with more Hispanic adolescents being treated in the West (White: 21.9%; Black: 8.9%; Hispanic: 40.3%; Other: 29.3%) at small hospitals (White: 14.0%; Black: 13.9%; Hispanic: 16.2%; Other: 7.1%). Baseline comorbidities were similar between the cohorts. The use of blood transfusions was significantly greater in the Black cohort compared to the other racial groups (White: 16.7%; Black: 25.0%; Hispanic: 24.5%; Other: 22.7%, p < 0.001). The number of vertebral levels involved differed significantly between the cohorts (p < 0.001), with the majority of patients having 9-levels or greater involved (White: 80.9%; Black: 81.7%; Hispanic: 84.3%; Other: 67.3%). The rate of complications encountered during admission was greatest in the Other cohort (White: 21.9%; Black: 23.6%; Hispanic: 22.2%; Other: 34.9%, p < 0.001). While LOS was similar between the cohorts (p = 0.702), median total cost of admission was highest for Hispanic patients (White: $49,340 [37,908-65,078]; Black: $47,787 [37,718-64,670]; Hispanic: $54,718 [40,689-69,266]; Other: $54,110 [41,292-71,540], p < 0.001). CONCLUSIONS: Our study suggests that race may not have a significant impact on surgical outcomes after elective posterior spine surgery for adolescent idiopathic scoliosis. Further studies are necessary to corroborate our findings.

Independent Association of Obesity and Nonroutine Discharge Disposition After Elective Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Myelopathy.

OBJECTIVE: The prevalence of obesity continues to rise in the United States at a disparaging rate. Although previous studies have attempted to identify the influence obesity has on short-term outcomes following elective spine surgery, few studies have assessed the impact on discharge disposition following anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). The aim of this study was to determine whether obesity impacts the hospital management, cost, and discharge disposition after elective ACDF for adult CSM. METHODS: The National Inpatient Sample database was queried using the International Classification of Diseases, 10th revision, Clinical Modification, coding system to identify all (≥18 years) patients with a primary diagnosis of CSM undergoing an elective ACDF for the years 2016 and 2017. Discharge weights were used to estimate national demographics, Elixhauser comorbidities, complications, length of stay, total cost of admission, and discharge disposition. RESULTS: There were 17,385 patients included in the study, of whom 3035 (17.4%) had obesity (no obesity: 14,350; obesity: 3035). The cohort with obesity had a significantly greater proportion of patients with 3 or more comorbidities compared with the cohort with no obesity (no obesity: 28.1% vs. obesity: 43.5%, P < 0.001). The overall complication rates were greater in the cohort with obesity (no obesity: 10.3% vs. obesity: 14.3%, P = 0.003). On average, the cohort with obesity incurred a total cost of admission $1154 greater than the cost of the cohort with no obesity (no obesity: $19,732 ± 11,605 vs. obesity: $20,886 ± 10,883, P = 0.034) and a significantly greater proportion of nonroutine discharges (no obesity: 16.6% vs. obesity: 24.2%, P < 0.001). In multivariate regression analysis, obesity, age, race, health care coverage, hospital bed size, region, comorbidity, and complication rates all were independently associated with nonroutine discharge disposition. CONCLUSIONS: Our study demonstrates that obesity is an independent predictor for nonroutine discharge disposition following elective anterior cervical discectomy and fusion for cervical spondylotic myelopathy.

Risk Factors Portending Extended Length of Stay After Suboccipital Decompression for Adult Chiari I Malformation.

OBJECTIVE: For adult patients undergoing surgical decompression for Chiari malformation type I (CM-I), the patient-level factors that influence extended length of stay (LOS) are relatively unknown. The aim of this study was to investigate the impact of patient-baseline comorbidities, demographics, and postoperative complications on extended LOS after intervention after adult CM-I decompression surgery. METHODS: A retrospective cohort study using the National Inpatient Sample years 2010-2014 was performed. Adults (≥18 years) with a primary diagnosis of CM-I undergoing surgical decompression were identified. Weighted patient demographics, comorbidities, complications, LOS, disposition, and total cost were recorded. A multivariate logistic regression was used to determine the odds ratio for risk-adjusted LOS. RESULTS: A total of 29,961 patients were identified, 6802 of whom (22.7%) had extended LOS. The extended LOS cohort had a significantly greater overall complication rate (normal LOS, 10.6% vs. extended LOS, 29.1%; P < 0.001) and total cost (normal LOS, $14,959 ± $6037 vs. extended LOS, $25,324 ± $21,629; P < 0.001) compared with the normal LOS cohort. On multivariate logistic regression, black race, income quartiles, private insurance, obstructive hydrocephalus, lack of coordination, fluid and electrolyte disorders, and paralysis were all independently associated with extended LOS. Additional duraplasty (P = 0.132) was not significantly associated with extended LOS after adjusting for other variables. The odds ratio for extended LOS was 2.07 (95% confidence interval, 1.59-2.71) for patients with 1 complication and 9.47 (95% confidence interval, 5.86-15.30) for patients with >1 complication. CONCLUSIONS: Our study shows that extended LOS after adult CM-I decompression surgery may be influenced by multiple patient-level factors.