Search Results

You are looking at 1 - 10 of 607 items for :

  • "survival analysis" x
Clear All
Restricted access

Toshikazu Kimura, Chikayuki Ochiai, Kensuke Kawai, Akio Morita and Nobuhito Saito

A neurysmal subarachnoid hemorrhage (aSAH) continues to be associated with high morbidity and death despite the refinement of treatment modalities. Rupture rates and risk factors associated with bleeding from unruptured cerebral aneurysms (UCAs) have been reported in many retrospective and several prospective studies using Kaplan-Meier curves and Cox proportional-hazards analyses. 2–5 , 7–10 , 12 , 13 , 16 , 19–23 , 25 , 26 However, Kaplan-Meier survival analysis is known to be less informative in the presence of competing risks, 6 which should be discussed in

Free access

Cyrus Elahi, Thiago Augusto Hernandes Rocha, Núbia Cristina da Silva, Francis M. Sakita, Ansbert Sweetbert Ndebea, Anthony Fuller, Michael M. Haglund, Blandina T. Mmbaga, João Ricardo Nickenig Vissoci and Catherine A. Staton

, for severe TBI. 1 , 9 , 22 , 27 The causes of these mortality rates are multifactorial, including the prehospital and inpatient care settings. Although prehospital quality data in low-resource settings are scarce, the availability of quality inpatient TBI registries from LMICs invites exploration of in-hospital care for patients with TBI in SSA. 22 A survival analysis performed using a Cox regression model is a powerful statistical technique to quantify the association between a treatment and outcome for two groups. 5 For TBI, this technique has potential to

Restricted access

Sunil Kukreja, Sudheer Ambekar, Anthony Hunkyun Sin and Anil Nanda

adjuvant RT), critical events (progression, recurrence, and death), time to critical events, and follow-up duration were included for the cumulative survival analysis. Case reports were excluded; however, an isolated patient from the case series whose age was ≤ 20 years was considered for inclusion. 32 In articles that described the outcomes in all age groups, patients in the first 2 decades of life were selected for the analysis. 1 , 2 , 7 , 13 , 17 , 19–21 , 26 , 32 Patients presenting with a history of previous surgery were not considered for inclusion. 7

Free access

Shelly Wang, Scellig Stone, Alexander G. Weil, Aria Fallah, Benjamin C. Warf, John Ragheb, Sanjiv Bhatia and Abhaya V. Kulkarni

surgeon), and postoperative outcome were collected and assessed. ETV/CPC failure was defined as the need for a second definitive hydrocephalus surgery with either repeat endoscopic treatment or shunt placement. A crude analysis of the ETV/CPC treatment failure of these 2 cohorts was performed using logistic regression and Cox proportional hazards regression survival analysis, to account for variable follow-up durations. A commonly used survival analysis method, the Cox model assumes that the relative failure rate (i.e., hazard ratio [HR]) of ETV/CPC remains constant

Restricted access

Zoe E. Teton, Daniel Blatt, Amr AlBakry, James Obayashi, Gulsah Ozturk, Vural Hamzaoglu, Philippe Magown, Nathan R. Selden, Kim J. Burchiel and Ahmed M. Raslan


Despite rapid development and expansion of neuromodulation technologies, knowledge about device and/or therapy durability remains limited. The aim of this study was to evaluate the long-term rate of hardware and therapeutic failure of implanted devices for several neuromodulation therapies.


The authors performed a retrospective analysis of patients’ device and therapy survival data (Kaplan-Meier survival analysis) for deep brain stimulation (DBS), vagus nerve stimulation (VNS), and spinal cord stimulation (SCS) at a single institution (years 1994–2015).


During the study period, 450 patients underwent DBS, 383 VNS, and 128 SCS. For DBS, the 5- and 10-year initial device survival was 87% and 73%, respectively, and therapy survival was 96% and 91%, respectively. For VNS, the 5- and 10-year initial device survival was 90% and 70%, respectively, and therapy survival was 99% and 97%, respectively. For SCS, the 5- and 10-year initial device survival was 50% and 34%, respectively, and therapy survival was 74% and 56%, respectively. The average initial device survival for DBS, VNS, and SCS was 14 years, 14 years, and 8 years while mean therapy survival was 18 years, 18 years, and 12.5 years, respectively.


The authors report, for the first time, comparative device and therapy survival rates out to 15 years for large cohorts of DBS, VNS, and SCS patients. Their results demonstrate higher device and therapy survival rates for DBS and VNS than for SCS. Hardware failures were more common among SCS patients, which may have played a role in the discontinuation of therapy. Higher therapy survival than device survival across all modalities indicates continued therapeutic benefit beyond initial device failures, which is important to emphasize when counseling patients.

Restricted access

Richard D. Penn, Michelle M. York and Judith A. Paice

critical to any analysis, survival curves provide the best way to view the performance of the catheter system. 7 The results in Fig. 2 provide a benchmark for any future catheter designs. As Fig. 3 clearly demonstrates, the “improved” design using a single catheter with an inner titanium coil was much worse, and this became obvious by 20 months. Future designs intended to increase longevity can similarly be compared to the reliability of the standard catheter (model 8703) by using survival analysis. The types of complications that were documented could have been

Restricted access

Frederick L. Hitti, Ashwin G. Ramayya, Brendan J. McShane, Andrew I. Yang, Kerry A. Vaughan and Gordon H. Baltuch

%) F Target 304 (95%) STN, 16 (5%) GPi Laterality 295 (92%) bilateral, 25 (8%) unilateral Mean ± SEM IPG longevity, yrs 3.7 ± 0.1 Values are number of patients (%) and means are presented ± SD unless otherwise indicated. Survival Analysis In a subset of patients who had at least 10 years of follow-up, we performed a Kaplan-Meier survival analysis ( Fig. 1 ). We found that 51% of patients survived through the follow-up interval. For patients who died during the follow-up interval, the mean age of death was 73 years. We performed multivariate regression analysis to

Full access

Abderrahmane Hamlat, Stephan Saikali, Jacques Chaperon, Michèle Le Calve, Daniel Gedouin, Mohamed Ben-Hassel and Yvon Guegan


Demonstration of the loss of chromosomes 1p and 19q in the presence of a brain neoplasm marks the emergence of genotype as a prognostic indicator. The authors report gene expression data for oligodendroglioma and correlate genotype with response to therapy. Gene expression subgroups may represent distinct types of disease.


Eighty-seven cases of supratentorial oligodendroglioma were selected from 145 cases treated in a single center between January 1990 and December 2001. Fluorescence in situ hybridization was used to determine the status of chromosomes 1p and 19q. Parameters evaluated included clinical data and radiological and histological features. Univariate and multivariate analyses were performed and a probability value less than 0.05 was considered significant.

The patients included 48 women and 39 men. The overall mean age at presentation was 45 years for women and 36 years for men (p = 0.006). The univariate analysis identified the following as favorable prognostic factors: younger patient age (p = 10−5), female sex (p = 0.0025), seizure as a presenting symptom (p = 10−5), normal clinical examination (p = 10−5), absence of lesion enhancement on neuroimaging studies (p = 0.0231), lack of histological necrosis (p = 0.0003), absence of mitoses (p = 0.0014), 1p and 19q deletions (p = 0.0001), absence of recurrence (p = 0.0021), and adjuvant radiotherapy and/or chemotherapy (p = 10−5). The multivariate analysis identified patient age (p = 10−5) and chromosomal anomalies (p = 0.002) as independently linked to survival. Three molecular subtypes emerged: oligodendroglioma with 1p and 19q deletions, oligodendroglioma demonstrating polysomia and a lack of meaningful response to radiotherapy or chemotherapy, and oligodendroglioma with no 1p-9q deletion in which partial response was seen.


According to our data, oligodendrogliomas could be divided into three molecular subtypes. Although chemotherapy seems efficient for managing this tumor, additional studies should be conducted to compare the efficacy of radiotherapy and chemotherapy.

Free access

Thara Tunthanathip, Sakchai Sae-heng, Thakul Oearsakul, Ittichai Sakarunchai, Anukoon Kaewborisutsakul and Chin Taweesomboonyat

purulent drainage comes from a drain that is placed into the organ/space (e.g., ventriculostomy); the main part of an abscess/other infection deeper than the fascial/muscle layers is present; organisms are identified from an aseptically obtained fluid or tissue in the organ/space by a culture; or there is evidence of infection involving the organ/space that is detected on gross anatomical or histopathological exam or on imaging. 6 , 7 Descriptive Statistics and Survival Analysis Clinical characteristics and therapeutic factors were first described using descriptive

Restricted access

Postoperative irradiation for subtotally resected meningiomas

A retrospective analysis of 140 patients treated from 1967 to 1990

Brian J. Goldsmith, William M. Wara, Charles B. Wilson and David A. Larson

radiographic data obtained from CT and/or MR imaging and the surgeon's description. In general, for benign meningiomas, the treatment volume included the gross tumor remnant after subtotal resection and a 1- to 2-cm margin of adjacent brain. For malignant meningiomas, the volume generally included the preoperative tumor volume and a 1- to 3-cm margin. Survival Analysis Rates of actuarial overall survival, intercurrent disease-specific survival, and progression-free survival were calculated (using the life-table method 17 ) from the date of initial subtotal resection