Development and Validation of a Simplified m-Group Regression Model

1976 ◽  
Vol 1 (2) ◽  
pp. 157 ◽  
Author(s):  
Kazuo Shigemasu
1976 ◽  
Vol 1 (2) ◽  
pp. 157-180 ◽  
Author(s):  
Kazuo Shigemasu

This study is an application and specialization of the Bayesian linear model developed by Lindley and Smith (1972). The context is m-group regression and the application to the prediction of grade point average. The specialization involves the assumption of homogeneity of regression coefficients (but not intercepts) across groups. Empirical cross-validations are conducted to compare the predictive efficiency of this model with that of the full m-group regression and several least squares methods in the context of educational selection.


2021 ◽  
pp. 103770
Author(s):  
Taran Skjerdal ◽  
Lars Erik Gangsei ◽  
Ole Alvseike ◽  
Kyrre Kausrud ◽  
Alessandra De Cesare ◽  
...  

2013 ◽  
Vol 10 (7) ◽  
pp. 1057-1067 ◽  
Author(s):  
Gerda Jimmy ◽  
Roland Seiler ◽  
Urs Maeder

Background:Accelerometry has been established as an objective method that can be used to assess physical activity behavior in large groups. The purpose of the current study was to provide a validated equation to translate accelerometer counts of the triaxial GT3X into energy expenditure in young children.Methods:Thirty-two children aged 5–9 years performed locomotor and play activities that are typical for their age group. Children wore a GT3X accelerometer and their energy expenditure was measured with indirect calorimetry. Twenty-one children were randomly selected to serve as development group. A cubic 2-regression model involving separate equations for locomotor and play activities was developed on the basis of model fit. It was then validated using data of the remaining children and compared with a linear 2-regression model and a linear 1-regression model.Results:All 3 regression models produced strong correlations between predicted and measured MET values. Agreement was acceptable for the cubic model and good for both linear regression approaches.Conclusions:The current linear 1-regression model provides valid estimates of energy expenditure for ActiGraph GT3X data for 5- to 9-year-old children and shows equal or better predictive validity than a cubic or a linear 2-regression model.


2021 ◽  
Author(s):  
Wenbo He ◽  
Changwu Xu ◽  
Xiaoying Wang ◽  
Jiyong Lei ◽  
Qinfang Qiu ◽  
...  

Abstract Background: This study aimed to develop and validate a nomogram to predict probability of in-stent restenosis (ISR) in patients undergoing percutaneous coronary intervention (PCI). Methods: Patients undergoing PCI with drug-eluting stents between July 2009 and August 2011 were retrieved from a cohort study in a high-volume PCI center, and further randomly assigned to training and validation sets. The least absolute shrinkage and selection operator (LASSO) regression model was used to screen out significant features for construction of nomogram. Multivariable logistic regression analysis was applied to build a nomogram-based predicting model incorporating the variables selected in the LASSO regression model. The area under the curve (AUC) of the receiver operating characteristics (ROC), calibration plot and decision curve analysis (DCA) were performed to estimate the discrimination, calibration and utility of the nomogram model respectively.Results: A total of 463 patients with DES implantation were enrolled and randomized in the development and validation sets. The predication nomogram was constructed with five risk factors including prior PCI, hyperglycemia, stents in left anterior descending artery (LAD), stent type, and absence of clopidogrel, which proved reliable for quantifying risks of ISR for patients with stent implantation. The AUC of development and validation set were 0.706 and 0.662, respectively, indicating that the prediction model displayed moderate discrimination capacity to predict restenosis. The high quality of calibration plots in both datasets demonstrated strong concordance performance of the nomogram model. Moreover, DCA showed that the nomogram was clinically useful when intervention was decided at the possibility threshold of 9%, indicating good utility for clinical decision-making.Conclusions: The individualized prediction nomogram incorporating 5 commonly clinical and angiographic characteristics for patients undergoing PCI can be conveniently used to facilitate early identification and improved screening of patients at higher risk of ISR.


2015 ◽  
Vol 5 (2) ◽  
pp. 99-123 ◽  
Author(s):  
Jeremy N.V Miles ◽  
Magdalena Kulesza ◽  
Brett Ewing ◽  
Regina A Shih ◽  
Joan S Tucker ◽  
...  

Purpose – When researchers find an association between two variables, it is useful to evaluate the role of other constructs in this association. While assessing these mediation effects, it is important to determine if results are equal for different groups. It is possible that the strength of a mediation effect may differ for males and females, for example – such an effect is known as moderated mediation. The paper aims to discuss these issues. Design/methodology/approach – Participants were 2,532 adolescents from diverse ethnic/racial backgrounds and equally distributed across gender. The goal of this study was to investigate parental respect as a potential mediator of the relationship between gender and delinquency and mental health, and to determine whether observed mediation is moderated by gender. Findings – Parental respect mediated the association between gender and both delinquency and mental health. Specifically, parental respect was a protective factor against delinquency and mental health problems for both females and males. Practical implications – Demonstrated the process of estimating models in Lavaan, using two approaches (i.e. single group regression and multiple group regression model), and including covariates in both models. Originality/value – The authors demonstrate the process of estimating these models in Lavaan, using two approaches, a single group regression model and a multiple group model, and the authors demonstrate how to include covariates in these models.


Sign in / Sign up

Export Citation Format

Share Document