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Concept: Univariate

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Introduction The analysis of predictive factors of response may aid in predicting which patients with advanced renal cell carcinoma (RCC) would be good candidates for systemic treatments. Materials and methods The expression of several biomarkers was retrospectively analyzed using immunohistochemistry (IHC), as well as 2 analytical variables in 135 patients with advanced RCC treated with cytokines (CK) and/or new targeted drugs (NTD). Results 67 patients were treated solely with NTD and 68 with CK (23 also received NTD). Univariate analysis: HIF1α did not correlate significantly with response to these drugs. Overexpression of CAIX was associated with more responses (%) to NTD (64.7 vs. 21.1; p = 0.004) and CK (22.6 vs. 0; p = 0.038). PTEN demonstrated predictive value of response to sunitinib (70.8 vs. 34.1; p = 0.005). p21 was associated with a lower response to sunitinib (35.9 vs. 65.4; p = 0.025). Thrombocytosis was not significantly associated with response to NTD, although it was with CK (0 vs. 20; p = 0.017). Neutrophilia correlated with a lower response to NTD (29.6 vs. 57.5; p = 0.045), although not with CK. Multivariate analysis: Overexpression of CAIX was an independent predictor of significantly higher response to NTD and CK; OR = 8.773 (p < 0.001). Conclusions Our findings highlight the usefulness of CAIX in selecting patients with advanced RCC as candidates for systemic treatment. PTEN and p21 may be important in predicting response to sunitinib. Thrombocytosis and neutrophilia correlate well with response to CK and NTD, respectively.

Concepts: Scientific method, Multivariate statistics, Univariate, Renal cell carcinoma

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BACKGROUND: Prosthetic reconstruction using human acellular dermis (ADM) is a common practice in breast reconstruction. AlloDerm and FlexHD are two different forms of ADM, each with unique characteristics. No studies have directly compared the postoperative complications of these 2 products. METHODS: The outcomes of 547 consecutive implant-based breast reconstructions were reviewed. RESULTS: Reconstruction was performed in 382 consecutive women (547 total breasts), employing mostly immediate reconstruction (81%). Mean follow-up was 6.4 months. Among immediate reconstructions, 165 used AlloDerm and 97 used FlexHD. Complications were similar by univariate analysis. In multivariate analysis, smoking and higher initial implant fill were risk factors for delayed healing. The use of FlexHD, single-stage reconstruction, and smoking were independent risk factors for implant loss. CONCLUSIONS: There is no significant difference in the complication rates between AlloDerm and FlexHD in immediate breast reconstruction. Multivariate analysis suggests that FlexHD may be a risk factor for implant loss.

Concepts: Risk, Multivariate statistics, Difference, Breast, Univariate, Breast reconstruction, Breast implant, Breast reduction

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The present study investigated the clinico-pathological features of fallopian tube malignancy (FTM) and elucidated the biological behavior of this disorder. Data were compiled concerning FTM from 68 patients from 7 institutes. The patients included 60 cases with fallopian tube carcinoma and 8 cases with fallopian tube carcinosarcoma. The clinical stage was stage III or higher in 72% of the cases. A complete response or partial response was achieved in 56 and 10 of the 68 patients with FTM, respectively, indicating a response rate of 97.1%. The median observation period for FTM was 41 months (3 to 126 months). Three of the 19 patients with stage I/II disease (16%) and 31 of the 49 patients with stage III/IV disease (63%) experienced recurrence, with a median progression-free survival of 17.5 months, and a 3-year overall survival of 77.2%. Regarding the site of recurrence, local intraperitoneal recurrence (26.2%) and solitary recurrences in lymph nodes (19.0%) and in the liver (16.7%) were relatively frequent. Secondary debulking surgery (SDS) was performed in 15 patients (44%) out of the 34 recurrent FTMs. Conversely, recurrence was associated with ascites (carcinomatous peritonitis) in 4 of the 34 recurrent patients, but all 4 patients died. The median survival period after recurrence was 28 months: 7.5 and 30 months with and without ascites, respectively (P<0.001). A univariate analysis showed that prognosis was significantly correlated only with whether SDS could be performed. These results suggest that since FTM frequently results in solitary recurrence, aggressive recurrence treatment including SDS could improve prognosis.

Concepts: Cancer, Cancer staging, Lymph node, Lymph, Univariate, Fallopian tube, Fallopian tube cancer, Recurrence relation

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BACKGROUND: Reasons for asthma hospitalizations are dynamic and complex. Comorbid conditions are important contributors to most chronic diseases today. We aim to characterize and describe risk factors associated with hospitalizations due to asthma in the Languedoc-Roussillon region (France) in 2009. METHODS: Programme de Médicalisation des Systèmes d'Information (PMSI) data records from 2009 were sorted using selected International Classification of Diseases (ICD10) codes eliciting three groups of asthma hospitalizations according to acute severity. All available data including demographics, comorbid conditions, past hospitalizations either related or unrelated to asthma, seasonality and distance to medical facilities were used to compare the subjects within the three groups. RESULTS: One thousand two hundred and eighty-nine hospitalizations due to asthma exacerbation were found, concerning 1122 patients. We observed significant differences within the groups, using univariate analysis, concerning duration of hospitalizations (mean ± SD, 4.9 ± 5.9 days vs 6.4 ± 6.8 vs 15.8 ± 16.8, P < 0.001), deaths (percentage, 0.03% vs 1.50% vs 9.20%, P < 0.001) and numbers of comorbid conditions (0.80 ± 0.95 vs 0.75 ± 0.97 vs 1.74 ± 1.36, P < 0.001). Recurrent admissions for asthma during the period 2006-2008 were significantly more frequent in the more severe group (1.93 ± 3.91 vs 2.56 ± 4.47 vs 2.81 ± 3.97, P = 0.006). In the multivariate model, age and number of comorbid conditions were independently associated with severe hospitalizations and deaths. CONCLUSIONS: Asthma hospitalizations can be appropriately assessed using PMSI coding databases. In this study, age and the presence of comorbid conditions are the major risk factors for asthma hospitalizations and deaths.

Concepts: Asthma, Chronic, 1000, Univariate, Acute, Languedoc wine, Languedoc-Roussillon, Pyrénées-Orientales

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PURPOSE: Segmentation and diffusion-tensor-imaging of the corpus callosum (CC) have been linked to gait impairment. However, such measurements are impracticable in clinical routine. The purpose of this study was to evaluate the association between simple linear measurements of CC thickness with gait. METHODS: Two hundred and seventy-two community-dwelling subjects underwent neurological assessment and brain MRI. Mid-sagittal reformats of T1-weighted images were used to determine CC thickness. The association of measurements with clinical evaluation of gait was assessed by multivariate regression, controlling for numerous clinical and imaging confounders. Differences in CC thickness were, moreover, compared between subgroups with no, moderate or severe impairment of gait. RESULTS: In univariate analyses, thickness of the genu and body of CC but not the splenium were associated with postural stability (P < 0.01). Multivariate regression revealed thickness of CC genu as the only imaging variable independently associated with gait (P = 0.01). Genu thickness was significantly different between subjects with high and low (P = 0.0003) or high and moderate (P = 0.001) risk of fall. CONCLUSION: Atrophy of the CC genu is an imaging marker of gait impairment in the elderly suggesting higher risk of fall. Simple linear measurements of CC can help in MRI evaluation of patients with gait impairment. KEY POINTS : • Regional atrophy of the corpus callosum reflects disruption of gait regulation • Genu thickness on cranial MRI is an independent marker of gait impairment • Findings help in the MRI evaluation of patients with gait impairment.

Concepts: Brain, Magnetic resonance imaging, Assessment, Corpus callosum, Univariate, Splenium, Agenesis of the corpus callosum, Genu of the corpus callosum

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Trochanteric overgrowth is one of the major residual deformities after the treatment of Legg-Calvé-Perthes disease. The present study was designed to determine the predictive factors for trochanteric overgrowth at skeletal maturity in patients with the disease. Medical records and radiographs of 45 Legg-Calvé-Perthes disease patients who were treated with containment therapy at our institution were reviewed retrospectively. Univariate analysis was carried out to determine the predictors for trochanteric overgrowth using the Mann-Whitney U-test for continuous variables and the Pearson test for categorical variables. Independent multivariate predictors were identified using logistic regression analysis. Trochanteric overgrowth, defined as articulotrochanteric distance less than +5 mm, was observed in 10 patients (22%). There was a strong correlation between the final Stulberg outcome and trochanteric overgrowth (P=0.0003). Lateral pillar height was the only statistically significant predictor for trochanteric overgrowth at skeletal maturity in univariate and multivariate analyses. The risk for the development of trochanteric overgrowth was much greater in the lateral pillar C hip (44%) than in the lateral pillar B or B/C hip (10%). For the patients with decreased lateral pillar height, a careful follow-up is necessary to make an early decision of prophylactic epiphyseodesis of the greater trochanter.

Concepts: Scientific method, Regression analysis, Logistic regression, Statistics, Prediction, Multivariate statistics, Mann–Whitney U, Univariate

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Mantle cell lymphoma (MCL) is characterized by a variable clinical course in which patients can experience indolent disease or frequent relapses despite a good initial response to conventional therapy. Risk stratification of MCL is most frequently performed using the MCL International Prognostic Index (MIPI). Recent studies indicate that the peripheral blood absolute monocyte count (AMC) and tumour-associated macrophages may reflect the state of the tumour microenvironment in lymphomas. The significance of AMC and tumour-associated macrophages in the clinical course of MCL is unknown. The prognostic impact of the AMC, of CD68 expression and of CD163 expression was retrospectively examined in 103 MCL samples using the receiver operating characteristic curved. Patients with an AMC ≥ 375 cells/μL at diagnosis were more likely to present with advanced-stage disease (p = 0.026), leukocytosis (p < 0.001), lymphocytosis (p = 0.01) and granulocytosis (p = 0.003). On univariate analysis, a high AMC (≥375 cells/μL) correlated with poorer overall survival (OS) (p = 0.01). Neither CD68 nor CD163 expression was significantly associated with either OS or event-free survival. Multivariate analysis showed that a high AMC was a prognostic factor for OS, independent of the MIPI [hazards ratio (HR), 1.811; 95% confidence interval, 1.018-3.223; p = 0.043]. This study demonstrates that the AMC at the time of diagnosis is an independent prognostic factor for OS in MCL, which suggests the possibility that AMC may be used in addition to the MIPI to predict outcome in patients with MCL. Copyright © 2013 John Wiley & Sons, Ltd.

Concepts: Monocyte, Cancer, Macrophage, Multivariate statistics, Hematology, Prognosis, Univariate, Mantle cell lymphoma

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Demonstrating bioequivalence of several pharmacokinetic (PK) parameters, such as AUC and Cmax , that are calculated from the same biological sample measurements is in fact a multivariate problem, even though this is neglected by most practitioners and regulatory bodies, who typically settle for separate univariate analyses. We believe, however, that a truly multivariate evaluation of all PK measures simultaneously is clearly more adequate. In this paper, we review methods to construct joint confidence regions around multivariate normal means and investigate their usefulness in simultaneous bioequivalence problems via simulation. Some of them work well for idealised scenarios but break down when faced with real-data challenges such as unknown variance and correlation among the PK parameters. We study the shapes of the confidence regions resulting from different methods, discuss how marginal simultaneous confidence intervals for the individual PK measures can be derived, and illustrate the application to data from a trial on ticlopidine hydrochloride. An R package is available.

Concepts: Statistics, Sample size, Confidence interval, Normal distribution, Prediction interval, Student's t-distribution, Univariate, Confidence region

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Only a tiny fraction of the data and metadata produced by an fMRI study is finally conveyed to the community. This lack of transparency not only hinders the reproducibility of neuroimaging results but also impairs future meta-analyses. In this work we introduce NIDM-Results, a format specification providing a machine-readable description of neuroimaging statistical results along with key image data summarising the experiment. NIDM-Results provides a unified representation of mass univariate analyses including a level of detail consistent with available best practices. This standardized representation allows authors to relay methods and results in a platform-independent regularized format that is not tied to a particular neuroimaging software package. Tools are available to export NIDM-Result graphs and associated files from the widely used SPM and FSL software packages, and the NeuroVault repository can import NIDM-Results archives. The specification is publically available at: http://nidm.nidash.org/specs/nidm-results.html.

Concepts: Scientific method, Statistics, Neuroimaging, Neuroscience, Univariate, Best practice, Export, Package

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Prediction of adult performance from early age talent identification in sport remains difficult. Talent identification research has generally been performed using univariate analysis, which ignores multivariate relationships. To address this issue, this study used a novel higher-dimensional model to orthogonalize multivariate anthropometric and fitness data from junior rugby league players, with the aim of differentiating future career attainment. Anthropometric and fitness data from 257 Under-15 rugby league players was collected. Players were grouped retrospectively according to their future career attainment (i.e., amateur, academy, professional). Players were blindly and randomly divided into an exploratory (n = 165) and validation dataset (n = 92). The exploratory dataset was used to develop and optimize a novel higher-dimensional model, which combined singular value decomposition (SVD) with receiver operating characteristic analysis. Once optimized, the model was tested using the validation dataset. SVD analysis revealed 60 m sprint and agility 505 performance were the most influential characteristics in distinguishing future professional players from amateur and academy players. The exploratory dataset model was able to distinguish between future amateur and professional players with a high degree of accuracy (sensitivity = 85.7%, specificity = 71.1%; p<0.001), although it could not distinguish between future professional and academy players. The validation dataset model was able to distinguish future professionals from the rest with reasonable accuracy (sensitivity = 83.3%, specificity = 63.8%; p = 0.003). Through the use of SVD analysis it was possible to objectively identify criteria to distinguish future career attainment with a sensitivity over 80% using anthropometric and fitness data alone. As such, this suggests that SVD analysis may be a useful analysis tool for research and practice within talent identification.

Concepts: Binary classification, Singular value decomposition, Identification, Univariate, Matrix, Rugby league, Singular value