scholarly journals Comparison of Splitting Methods on Survival Tree

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Asanao Shimokawa ◽  
Yohei Kawasaki ◽  
Etsuo Miyaoka
Keyword(s):  
Regression Tree ◽  
Splitting Methods ◽  
Classification And Regression Tree ◽  
Rank Test ◽  
Test Statistic ◽  
Survival Trees ◽  
Martingale Residual ◽  
Log Likelihood ◽  
Sample Test ◽  
Deviance Residual

AbstractWe compare splitting methods for constructing survival trees that are used as a model of survival time based on covariates. A number of splitting criteria on the classification and regression tree (CART) have been proposed by various authors, and we compare nine criteria through simulations. Comparative studies have been restricted to criteria that suppose the survival model for each terminal node in the final tree as a non-parametric model. As the main results, the criteria using the exponential log-likelihood loss, log-rank test statistics, the deviance residual under the proportional hazard model, or square error of martingale residual are recommended when it appears that the data have constant hazard with the passage of time. On the other hand, when the data are thought to have decreasing hazard with passage of time, the criterion using the two-sample test statistic, or square error of deviance residual would be optimal. Moreover, when the data are thought to have increasing hazard with the passage of time, the criterion using the exponential log-likelihood loss, or impurity that combines observed times and the proportion of censored observations would be the best. We also present the results of an actual medical research to show the utility of survival trees.

scholarly journals Multicenter Study of the Relationship between Carbapenem MIC Values and Clinical Outcome of Patients with Acinetobacter Bacteremia

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Ya-Sung Yang ◽  
Yung-Chih Wang ◽  
Shu-Chen Kuo ◽  
Chung-Ting Chen ◽  
Chang-Pan Liu ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Regression Tree ◽  
Classification And Regression Tree ◽  
Rank Test ◽  
Bivariate Analysis ◽  
Content Type ◽  
Medical Centers ◽  
Regression Tree Analysis ◽  
Log Rank Test ◽  
The Relationship

ABSTRACT The Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) offer different recommendations for carbapenem MIC susceptibility breakpoints for Acinetobacter species. In addition, the clinical efficacy of the intermediate category remains uncertain. This study was designed to determine the optimal predictive breakpoints based on the survival of patients with Acinetobacter bacteremia treated with a carbapenem. We analyzed the 30-day mortality rates of 224 adults who received initial carbapenem monotherapy for the treatment of Acinetobacter bacteremia at 4 medical centers over a 5-year period, according to the carbapenem MICs of the initial isolates. The 30-day mortality was about 2-fold greater in patients whose isolates had carbapenem MICs of ≥8 mg/liter than in those with isolates with MICs of ≤4 mg/liter. The differences were significant by bivariate analysis (53.1% [60/113] versus 25.2% [28/111], respectively; P < 0.001) and on survival analysis by the log rank test (P < 0.001). Classification and regression tree analysis revealed a split between MICs of 4 and 8 mg/liter and predicted the same difference in mortality, with a P value of <0.001. Carbapenem treatment for Acinetobacter bacteremia caused by isolates with carbapenem MICs of ≥8 mg/liter was an independent predictor of 30-day mortality (odds ratio, 4.218; 95% confidence interval, 2.213 to 8.039; P < 0.001). This study revealed that patients with Acinetobacter bacteremia treated with a carbapenem had a more favorable outcome when the carbapenem MICs of their isolates were ≤4 mg/liter than those with MICs of ≥8 mg/liter.

Correlation of mesothelin expression and CD8 tumor infiltrating lymphocytes with prognosis in cholangiocarcinoma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15650-e15650
Author(s):  
Paul Raymond Kunk ◽  
Joseph Mounir Obeid ◽  
Kevin Winters ◽  
Patcharin Pramoonjago ◽  
Dirk G. Brockstedt ◽  
...  
Keyword(s):  
Overall Survival ◽  
Tumor Cells ◽  
Regression Tree ◽  
Tumor Infiltrating Lymphocytes ◽  
Classification And Regression Tree ◽  
Rank Test ◽  
Risk Of Death ◽  
Unmet Treatment Need ◽  
Infiltrating Lymphocytes ◽  
Mesothelin Expression

e15650 Background: Cholangiocarcinoma (CC) is a rapidly progressing malignancy with an unmet treatment need. Little is known about the CC tumor immune microenvironment or about relevant antigenic targets. We hypothesized that lack of T cell infiltration or PD-L1 expression may identify patients at high risk of death, and that mesothelin may be a relevant antigenic target. Methods: A retrospective analysis was conducted of CC tumors at the University of Virginia from 2000-2014. TMAs were constructed of 3-4 cores from each tumor and were stained by IHC for CD4 and CD8 tumor infiltrating lymphocytes (TILs), mesothelin and PD-L1. TMAs were scanned using the Leica SCN400 and analyzed using the Digital Image Hub software. Stain intensity thresholds for defining positive cells were determined by two users and recorded as an average of all cores from each tumor. Mesothelin and PD-L1 expression were measured as a percentage of positive tumor cells. TILs and protein expression were analyzed for association with overall survival, grouped as high or low expression based either on the median or the 33rdpercentile. Correlation with overall survival was assessed using a log rank test and a classification and regression tree with p-values < 0.05 being considered statistically significant. Results: Ninety-nine tumors were available for analysis: 26 intrahepatic, 37 hilar, and 36 distal. PD-L1 and mesothelin expression > 1% of tumor cells were found in 16% and 92% of tumors, respectively. CD4 and CD8 TILs were found in nearly all tumors (98% and 96%), with the majority showing intraepithelial CD4 and CD8 infiltration (73% and 68%). There were no significant associations between survival and PD-L1, mesothelin, or CD4 and CD8 infiltration. However when considered together, the group with low mesothelin/low CD8 (each below 33rdpercentile) had worse survival (9.1 months) compared to high mesothelin/high CD8 (25 months), high mesothelin/low CD8 (30.1 months) and low mesothelin/high CD8 (26.1 months), p = 0.015. Conclusions: CC tumors that lack CD8 infiltration and mesothelin expression have a poor prognosis. Mesothelin represents an attractive target in cholangiocarcinoma, opening the door for future immunotherapy for CC.

Prevention of Stunting Through Health Education in Parents of Pre-School Children

2020 ◽  
Vol 9 (1) ◽  
pp. 70-77
Author(s):  
Kili Astarani ◽  
Desi Natalia Trijayanti Idris ◽  
Aurelia Rizky Oktavia
Keyword(s):  
Health Education ◽  
School Children ◽  
Parental Knowledge ◽  
Rank Test ◽  
Visual Aids ◽  
Test Statistic ◽  
Knowledge Measurement ◽  
Analysis Technique ◽  
Post Test ◽  
Signed Rank Test

This study aims to analyze the effect of pre-school age children's health education on stunting in the Setia Bakti Kediri Kindergarten. The design of this study used a pre-experimental pre-post test. Subjects were parents who had pre-school children with 49 respondents in the Setia Bakti Kediri Kindergarten. Retrieval of data from 29 - 31 May 2019. Randomization technique with purposive sampling. The variable of this study is parental knowledge. Measurement of knowledge with a questionnaire. Health education is carried out for 60 minutes using lecture methods, audio media, visual aids, and booklets. Research analysis technique with the Wilcoxon Signed Rank Test statistic test. The results of this study indicate that there is an influence of health education about stunting on the knowledge of parents of pre-school children in Setia Bakti Kediri Kindergarten. Health education about stunting increases parental knowledge

GCS-Pupil Score Has a Stronger Association with Mortality and Poor Functional Outcome than GCS Alone in Pediatric Severe Traumatic Brain Injury

2021 ◽  
pp. 1-8
Author(s):  
Binod Balakrishnan ◽  
Heather VanDongen-Trimmer ◽  
Irene Kim ◽  
Sheila J. Hanson ◽  
Liyun Zhang ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Functional Outcome ◽  
Cerebral Performance Category ◽  
Regression Tree ◽  
Classification And Regression Tree ◽  
Continuous Variables ◽  
Poor Functional Outcome ◽  
Severity Scores ◽  
Pupil Reactivity

<b><i>Background:</i></b> The Glasgow Coma Scale (GCS), used to classify the severity of traumatic brain injury (TBI), is associated with mortality and functional outcomes. However, GCS can be affected by sedation and neuromuscular blockade. GCS-Pupil (GCS-P) score, calculated as GCS minus Pupil Reactivity Score (PRS), was shown to better predict outcomes in a retrospective cohort of adult TBI patients. We evaluated the applicability of GCS-P to a large retrospective pediatric severe TBI (sTBI) cohort. <b><i>Methods:</i></b> Admissions to pediatric intensive care units in the Virtual Pediatric Systems (VPS, LLC) database from 2010 to 2015 with sTBI were included. We collected GCS, PRS (number of nonreactive pupils), cardiac arrest, abusive head trauma status, illness severity scores, pediatric cerebral performance category (PCPC) score, and mortality. GCS-P was calculated as GCS minus PRS. χ<sup>2</sup> or Fisher’s exact test and Mann-Whitney U test compared categorical and continuous variables, respectively. Classification and regression tree analysis identified thresholds of GCS-P and GCS along with other independent factors which were further examined using multivariable regression analysis to identify factors independently associated with mortality and unfavorable PCPC at PICU discharge. <b><i>Results:</i></b> Among the 2,682 patients included in the study, mortality was 23%, increasing from 4.7% for PRS = 0 to 80% for PRS = 2. GCS-P identified more severely injured patients with GCS-P scores 1 and 2 who had worse outcomes. GCS-P ≤ 2 had higher odds for mortality, OR = 68.4 (95% CI = 50.6–92.4) and unfavorable PCPC, OR = 17.3 (8.1, 37.0) compared to GCS ≤ 5. GCS-P ≤ 2 also had higher specificity and positive predictive value for both mortality and unfavorable PCPC compared to GCS ≤ 5. <b><i>Conclusions:</i></b> GCS-P, by incorporating pupil reactivity to GCS scoring, is more strongly associated with mortality and poor functional outcome at PICU discharge in children with sTBI.

scholarly journals Edible Insects: Preliminary Study about Perceptions, Attitudes, and Knowledge on a Sample of Portuguese Citizens

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 709
Author(s):  
Sofia G. Florença ◽  
Paula M. R. Correia ◽  
Cristina A. Costa ◽  
Raquel P. F. Guiné
Keyword(s):  
Nutritive Value ◽  
Meat Products ◽  
Regression Tree ◽  
Good Alternative ◽  
Classification And Regression Tree ◽  
Categorical Variables ◽  
Final Conclusion ◽  
Edible Insects ◽  
Chi Square ◽  
Alternative Sources

This study investigated the knowledge, attitudes, consumption habits, and degree of acceptability of edible insects (EI) or derived products among Portuguese consumers. This work consisted of a questionnaire survey, undertaken on a sample of 213 participants. For the treatment of data, basic descriptive statistics were used, complemented with chi-square tests to assess some associations between categorical variables. Moreover, a tree classification analysis was carried out using a classification and regression tree (CRT) algorithm with cross-validation. The results indicated that people tend to have correct perceptions about the sustainability issues associated with the use of insects as alternative sources of protein; however, the level of knowledge and overall perception about their nutritive value is low. Regarding the consumption of EI, it was found that only a small part of the participants had already eaten them, doing it mostly abroad, by self-initiative, in a restaurant or at a party or event. Additionally, it was found that the reluctance to consume insects is higher if they are whole, but when they are transformed into ingredients used in food formulations, the level of acceptance increases. Furthermore, men have shown to have a better perception about EI, be more informed about sustainability, and have a higher level of acceptability when compared to women. As a final conclusion, it was observed that the Portuguese still show some resistance to adhere to the use of insects as replacements for meat products, but the market of insect based products can be a good alternative to overpass the neophobia associated with this type of food.

scholarly journals Validation and verification of predictive salivary biomarkers for oral health

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nagihan Bostanci ◽  
Konstantinos Mitsakakis ◽  
Beral Afacan ◽  
Kai Bao ◽  
Benita Johannsen ◽  
...  
Keyword(s):  
Oral Health ◽  
Predictive Accuracy ◽  
Statistical Tests ◽  
Area Under The Curve ◽  
Regression Tree ◽  
High Sensitivity ◽  
Oral Health Status ◽  
Classification And Regression Tree ◽  
Cart Analysis ◽  
Salivary Biomarkers

AbstractOral health is important not only due to the diseases emerging in the oral cavity but also due to the direct relation to systemic health. Thus, early and accurate characterization of the oral health status is of utmost importance. There are several salivary biomarkers as candidates for gingivitis and periodontitis, which are major oral health threats, affecting the gums. These need to be verified and validated for their potential use as differentiators of health, gingivitis and periodontitis status, before they are translated to chair-side for diagnostics and personalized monitoring. We aimed to measure 10 candidates using high sensitivity ELISAs in a well-controlled cohort of 127 individuals from three groups: periodontitis (60), gingivitis (31) and healthy (36). The statistical approaches included univariate statistical tests, receiver operating characteristic curves (ROC) with the corresponding Area Under the Curve (AUC) and Classification and Regression Tree (CART) analysis. The main outcomes were that the combination of multiple biomarker assays, rather than the use of single ones, can offer a predictive accuracy of > 90% for gingivitis versus health groups; and 100% for periodontitis versus health and periodontitis versus gingivitis groups. Furthermore, ratios of biomarkers MMP-8, MMP-9 and TIMP-1 were also proven to be powerful differentiating values compared to the single biomarkers.

scholarly journals Implications of Lifestyle and Occupational Factors on the Risk of Breast Cancer in Shiftwork Nurses

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 649
Author(s):  
Javier Fagundo-Rivera ◽  
Regina Allande-Cussó ◽  
Mónica Ortega-Moreno ◽  
Juan Jesús García-Iglesias ◽  
Adolfo Romero ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Shift Work ◽  
Regression Tree ◽  
Night Work ◽  
Circadian Disruption ◽  
Classification And Regression Tree ◽  
Baseline Risk ◽  
Unhealthy Lifestyle ◽  
Cross Sectional ◽  
Occupational Factors

Shift work that involves circadian disruption has been highlighted as a likely carcinogenic factor for breast cancer in humans. Also, unhealthy lifestyle habits observed in night work nurses could be causally related to an increase in the incidence of estrogen-positive breast tumours in this population. Assessing baseline risk of breast cancer in nurses is essential. The objective of this study was to analyze the risk of breast cancer that nurses had in relation to their lifestyle and labour factors related to shift work. A cross-sectional descriptive study through a questionnaire about sociodemographic variables, self-perception of health, and working life was designed. The sample consisted of 966 nurses. The relationship between variables was tested. A binary logistic regression and a classification and regression tree were performed. The most significant labour variables in relation to the risk of breast cancer were the number of years worked (more than 16 years; p < 0.01; OR = 8.733, 95% CI = 2.811, 27.134) and the total years performing more than 3 nights per month (10 or more years; p < 0.05; OR = 2.294, 95% CI = 1.008, 5.220). Also, the nights worked throughout life (over 500; OR = 4.190, 95% CI = 2.118, 8.287) were significant in the analysis. Nurses who had or ever had breast cancer valued their self-perceived health more negatively (p < 0.001) and referred a lower quality of sleep (p < 0.001) than the non-cases nurses. The occupational factors derived from night work could have several impacts on nurses’ health and their family-work balance. Promoting healthy lifestyles, informing about shift work risks, and adjusting shift work schedules are critical methods to decrease the possible effects of circadian disruption in nurses.

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