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Dive into the research topics where Abraham Noorbakhsh is active.

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Featured researches published by Abraham Noorbakhsh.


Journal of Neurosurgery | 2014

Gross-total resection outcomes in an elderly population with glioblastoma: a SEER-based analysis

Abraham Noorbakhsh; Jessica A. Tang; Logan P. Marcus; Brandon A. McCutcheon; David D. Gonda; Craig S Schallhorn; Mark A. Talamini; David C. Chang; Bob S. Carter; Clark C. Chen

OBJECT There is limited information on the relationship between patient age and the clinical benefit of resection in patients with glioblastoma. The purpose of this study was to use a population-based database to determine whether patient age influences the frequency that gross-total resection (GTR) is performed, and also whether GTR is associated with survival difference in different age groups. METHODS The authors identified 20,705 adult patients with glioblastoma in the Surveillance, Epidemiology, and End Results (SEER) registry (1998-2009). Surgical practice patterns were defined by the categories of no surgery, subtotal resection (STR), and GTR. Kaplan-Meier and multivariate Cox regression analyses were used to assess the pattern of surgical practice and overall survival. RESULTS The frequency that GTR was achieved in patients with glioblastoma decreased in a stepwise manner as a function of patient age (from 36% [age 18-44 years] to 24% [age ≥ 75]; p < 0.001). For all age groups, glioblastoma patients who were selected for and underwent GTR showed a 2- to 3-month improvement in overall survival (p < 0.001) relative to those who underwent STR. These trends remained true after a multivariate analysis that incorporated variables including ethnicity, sex, year of diagnosis, tumor size, tumor location, and radiotherapy status. CONCLUSIONS Gross-total resection is associated with improved overall survival, even in elderly patients with glioblastoma. As such, surgical decisions should be individually tailored to the patient rather than an adherence to age as the sole clinical determinant.


Journal of Neurosurgery | 2014

Incidence and predictors of 30-day readmission for patients discharged home after craniotomy for malignant supratentorial tumors in California (1995–2010)

Logan P. Marcus; Brandon A. McCutcheon; Abraham Noorbakhsh; Ralitza P. Parina; David D. Gonda; Clark Chen; David C. Chang; Bob S. Carter

OBJECT Hospital readmission within 30 days of discharge is a major contributor to the high cost of health care in the US and is also a major indicator of patient care quality. The purpose of this study was to investigate the incidence, causes, and predictors of 30-day readmission following craniotomy for malignant supratentorial tumor resection. METHODS The longitudinal California Office of Statewide Health Planning & Development inpatient-discharge administrative database is a data set that consists of 100% of all inpatient hospitalizations within the state of California and allows each patient to be followed throughout multiple inpatient hospital stays, across multiple institutions, and over multiple years (from 1995 to 2010). This database was used to identify patients who underwent a craniotomy for resection of primary malignant brain tumors. Causes for unplanned 30-day readmission were identified by principle ICD-9 diagnosis code and multivariate analysis was used to determine the independent effect of various patient factors on 30-day readmissions. RESULTS A total of 18,506 patients received a craniotomy for the treatment of primary malignant brain tumors within the state of California between 1995 and 2010. Four hundred ten patients (2.2%) died during the index surgical admission, 13,586 patients (73.4%) were discharged home, and 4510 patients (24.4%) were transferred to another facility. Among patients discharged home, 1790 patients (13.2%) were readmitted at least once within 30 days of discharge, with 27% of readmissions occurring at a different hospital than the initial surgical institution. The most common reasons for readmission were new onset seizure and convulsive disorder (20.9%), surgical infection of the CNS (14.5%), and new onset of a motor deficit (12.8%). Medi-Cal beneficiaries were at increased odds for readmission relative to privately insured patients (OR 1.52, 95% CI 1.20-1.93). Patients with a history of prior myocardial infarction were at an increased risk of readmission (OR 1.64, 95% CI 1.06-2.54) as were patients who developed hydrocephalus (OR 1.58, 95% CI 1.20-2.07) or venous complications during index surgical admission (OR 3.88, 95% CI 1.84-8.18). CONCLUSIONS Using administrative data, this study demonstrates a baseline glioma surgery 30-day readmission rate of 13.2% in California for patients who are initially discharged home. This paper highlights the medical histories, perioperative complications, and patient demographic groups that are at an increased risk for readmission within 30 days of home discharge. An analysis of conditions present on readmission that were not present at the index surgical admission, such as infection and seizures, suggests that some readmissions may be preventable. Discharge planning strategies aimed at reducing readmission rates in neurosurgical practice should focus on patient groups at high risk for readmission and comprehensive discharge planning protocols should be implemented to specifically target the mitigation of potentially preventable conditions that are highly associated with readmission.


Journal of The American College of Surgeons | 2014

Long-Term Outcomes of Patients with Nonsurgically Managed Uncomplicated Appendicitis

Brandon A. McCutcheon; David C. Chang; Logan P. Marcus; Tazo Inui; Abraham Noorbakhsh; Craig S Schallhorn; Ralitza P. Parina; Francesca R. Salazar; Mark A. Talamini

BACKGROUND Emerging literature has supported the safety of nonoperative management of uncomplicated appendicitis. STUDY DESIGN Patients with emergent, uncomplicated appendicitis were identified by appropriate ICD-9 diagnosis codes in the California Office of Statewide Health Planning and Development database from 1997 to 2008. Rates of treatment failure, recurrence, and perforation after nonsurgical management were calculated. Factors associated with treatment failure, recurrence, and perforation were identified using multivariable logistic regression. Mortality, length of stay, and total charges were compared between treatment cohorts using matched propensity score analysis. RESULTS Of 231,678 patients with uncomplicated appendicitis, the majority (98.5%) were managed operatively. Of the 3,236 nonsurgically managed patients who survived to discharge without an interval appendectomy, 5.9% and 4.4% experienced treatment failure or recurrence, respectively, during a median follow-up of more than 7 years. There were no mortalities associated with treatment failure or recurrence. The risk of perforation after discharge was approximately 3%. Using multivariable analysis, race and age were significantly associated with the odds of treatment failure. Sex, age, and hospital teaching status were significantly associated with the odds of recurrence. Age and hospital teaching status were significantly associated with the odds of perforation. Matched propensity score analysis indicated that after risk adjustment, mortality rates (0.1% vs 0.3%; p = 0.65) and total charges (


Journal of Neurosurgery | 2014

Long-term follow-up of unruptured intracranial aneurysms repaired in California

David D. Gonda; Alexander A. Khalessi; Brandon A. McCutcheon; Logan P. Marcus; Abraham Noorbakhsh; Clark C. Chen; David C. Chang; Bob S. Carter

23,243 vs


Journal of Neurosurgery | 2015

Treatment biases in traumatic neurosurgical care: a retrospective study of the Nationwide Inpatient Sample from 1998 to 2009.

Brandon A. McCutcheon; David C. Chang; Logan P. Marcus; David D. Gonda; Abraham Noorbakhsh; Clark C. Chen; Mark A. Talamini; Bob S. Carter

24,793; p = 0.70) were not statistically different between operative and nonoperative patients; however, length of stay was significantly longer in the nonoperative treatment group (2.1 days vs 3.2 days; p < 0.001). CONCLUSIONS This study suggests that nonoperative management of uncomplicated appendicitis can be safe and prompts additional investigations. Comparative effectiveness research using prospective randomized studies can be particularly useful.


Annals of Surgery | 2017

How Far Are Patients Willing to Travel for Gastrectomy

Donna Marie L. Alvino; David C. Chang; Joel T. Adler; Abraham Noorbakhsh; Ginger Jin; John T. Mullen

OBJECT Using a database that enabled longitudinal follow-up, the authors assessed the long-term outcomes of unruptured cerebral aneurysms repaired by clipping or coiling. METHODS An observational analysis of the California Office of Statewide Health Planning and Development (OSHPD) database, which follows patients longitudinally in time and through multiple hospitalizations, was performed for all patients initially treated for an unruptured cerebral aneurysm in the period from 1998 to 2005 and with follow-up data through 2009. RESULTS Nine hundred forty-four cases (36.5%) were treated with endovascular coiling, 1565 cases (60.5%) were surgically clipped, and 76 cases were treated with both coiling and clipping. There was no significant difference in any demographic variable between the two treatment groups except for age (median: 55 years for the clipped group, 58 years for the coiled group, p < 0.001). Perioperative (30-day) mortality was 1.1% in patients with coiled aneurysms compared with 2.3% in those with clipped aneurysms (p = 0.048). The median follow-up was 7 years (range 4-12 years). At the last follow-up, 153 patients (16.2%) in the coiled group had died compared with 244 (15.6%) in the clipped group (p = 0.693). The adjusted hazard ratio for death at the long-term follow-up was 1.14 (95% CI 0.9-1.4, p = 0.282) for patients with endovascularly treated aneurysms. The incidence of intracranial hemorrhage was similar in the two treatment groups (5.9% clipped vs 4.8% coiled, p = 0.276). One hundred ninety-three patients (20.4%) with coiled aneurysms underwent additional hospitalizations for aneurysm repair procedures compared with only 136 patients (8.7%) with clipped aneurysms (p < 0.001). Cumulative hospital costs per patient for admissions involving aneurysm repair procedures were greater in the clipped group (median cost


Spine | 2015

Thirty-Day Perioperative Outcomes in Spinal Fusion by Specialty Within the NSQIP Database.

Brandon A. McCutcheon; Joseph D. Ciacci; Logan P. Marcus; Abraham Noorbakhsh; David D. Gonda; Randall McCafferty; William R. Taylor; Clark C. Chen; Bob S. Carter; David C. Chang

98,260 vs


World Journal of Surgery | 2014

An Efficient Risk Adjustment Model to Predict Inpatient Adverse Events after Surgery

Jamie E. Anderson; John Rose; Abraham Noorbakhsh; Mark A. Talamini; Samuel R. G. Finlayson; Stephen W. Bickler; David C. Chang

81,620, p < 0.001) through the follow-up. CONCLUSIONS For unruptured cerebral aneurysms, an observed perioperative survival advantage for endovascular coiling relative to that for surgical clipping was lost on long-term follow-up, according to data from an administrative database of patients who were not randomly allocated to treatment type. A cost advantage of endovascular treatment was maintained even though endovascularly treated patients were more likely to undergo subsequent hospitalizations for additional aneurysm repair procedures. Rates of aneurysm rupture following treatment were similar in the two groups.


Neuro-Oncology Practice | 2015

Survival trends of grade I, II, and III astrocytoma patients and associated clinical practice patterns between 1999 and 2010: A SEER-based analysis

Xuezhi Dong; Abraham Noorbakhsh; Brian R. Hirshman; Tianzan Zhou; Jessica A. Tang; David C. Chang; Bob S. Carter; Clark C. Chen

OBJECT This study was designed to assess the relationship between insurance status and likelihood of receiving a neurosurgical procedure following admission for either extraaxial intracranial hemorrhage or spinal vertebral fracture. METHODS A retrospective analysis of the Nationwide Inpatient Sample (NIS; 1998-2009) was performed. Cases of traumatic extraaxial intracranial hematoma and spinal vertebral fracture were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. Within this cohort, those patients receiving a craniotomy or spinal fusion and/or decompression in the context of an admission for traumatic brain or spine injury, respectively, were identified using the appropriate ICD-9 procedure codes. RESULTS A total of 190,412 patients with extraaxial intracranial hematoma were identified between 1998 and 2009. Within this cohort, 37,434 patients (19.7%) received a craniotomy. A total of 477,110 patients with spinal vertebral fracture were identified. Of these, 37,302 (7.8%) received a spinal decompression and/or fusion. On multivariate analysis controlling for patient demographics, severity of injuries, comorbidities, hospital volume, and hospital characteristics, uninsured patients had a reduced likelihood of receiving a craniotomy (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.71-0.82) and spinal fusion (OR 0.67, 95% CI 0.64-0.71) relative to insured patients. This statistically significant trend persisted when uninsured and insured patients were matched on the basis of mortality propensity score. Uninsured patients demonstrated an elevated risk-adjusted mortality rate relative to insured patients in cases of extraaxial intracranial hematoma. Among patients with spinal injury, mortality rates were similar between patients with and without insurance. CONCLUSIONS In this study, uninsured patients were consistently less likely to receive a craniotomy or spinal fusion for traumatic intracranial extraaxial hemorrhage and spinal vertebral fracture, respectively. This difference persisted after accounting for overall injury severity and patient access to high- or low-volume treatment centers, and potentially reflects a resource allocation bias against uninsured patients within the hospital setting. This information adds to the growing literature detailing the benefits of health reform initiatives seeking to expand access for the uninsured.


Annals of Vascular Surgery | 2018

Hospital Teaching Status and Readmission after Open Abdominal Aortic Aneurysm Repair

Madhukar S. Patel; Zhi Ven Fong; Brandon M. Wojcik; Abraham Noorbakhsh; Samuel E. Wilson; David C. Chang

Objective: To determine travel patterns for patients undergoing gastrectomy for cancer and to identify factors associated with patient decision. Background: Support for regionalization of complex surgery grows; however, little is known about the willingness of patients to travel for care. Furthermore, utilization of outcomes data in patients’ hospital selection processes is not well understood. Methods: Analysis of the California Office of Statewide Health Planning and Development database from 1996 to 2009. Outcome measures included total distance traveled and rate of bypassing the nearest gastrectomy-performing hospitals. Multivariate analyses to identify predictors of bypassing local hospitals were performed. Results: Total study population was 10,022. Majority (67.1%) of patients underwent gastrectomy at the nearest providing hospitals. Distance traveled to destination hospitals in California averaged 17.04 miles. Bypassing patients traveled approximately 16 miles beyond the nearest hospitals to receive care, selecting lower volume destination hospitals in 27.9% of cases. Annual gastrectomy volumes for nearest and for destination hospitals averaged 4.4 and 6.8 cases, respectively, and inhospital mortality rates were 5.9% and 4.8%, respectively. A few patients (19.2%) sought care at teaching hospitals. Rural county residence significantly reduced the likelihood of bypass (P < 0.001). High volume (>7 cases) and teaching status of destination hospitals (both P < 0.001) were predictive of hospital bypass, though no significant association between mortality rate and bypass was identified. Conclusions: The majority of gastric cancer patients underwent gastrectomy at providing hospitals nearest to home, reflecting little regionalization of gastrectomy in California. Patients’ hospital selection appears not to be driven by outcomes data.

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David C. Chang

University of California

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Bob S. Carter

University of California

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David D. Gonda

University of California

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Clark Chen

University of California

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