Results 71 to 80 of about 41,599 (261)

Quantile Estimation Based on the Log-Skew-t Linear Regression Model: Statistical Aspects, Simulations, and Applications

Stats
We propose a robust linear regression model assuming a log-skew-t distribution for the response variable, with the aim of exploring the association between the covariates and the quantiles of a continuous and positive response variable under skewness and
Raúl Alejandro Morán-Vásquez, Anlly Daniela Giraldo-Melo, Mauricio A. Mazo-Lopera   +2 more
doaj   +1 more source

New Onset of Fibromyalgia After Exposure to a Combat Environment: A Longitudinal Cohort Study

Arthritis Care &Research, EarlyView.
Objective Traumatic life events are hypothesized to be triggers for the onset of fibromyalgia. Posttraumatic stress disorder (PTSD) is a common comorbidity of fibromyalgia. However, limited prospective data are available on the development of fibromyalgia after exposure to high‐magnitude stress.
Jay B. Higgs, Willie J. Hale, Casey L. Straud, Jim Mintz, Stacey Young‐McCaughan, Kimberly D. Gomes, Chelsea J. Sterne, Katrina M. Lawrence‐Wolff, Alan J. Bartholomew, Kevin M. Kelly, Douglas M. Maurer, Catherine Vriend, Brett T. Litz, Douglas E. Williamson, Alan L. Peterson, for the STRONG STAR Consortium   +15 more
wiley   +1 more source

Developing and Evaluating a Laboratory‐Based Frailty Index for the Prediction of Long‐Term Health Outcomes in Systemic Lupus Erythematosus

Arthritis Care &Research, EarlyView.
Objective We aimed to construct and evaluate the first laboratory‐based frailty index (FI‐Lab) for predicting adverse outcomes in systemic lupus erythematosus (SLE) and to compare its predictive ability to that of an existing clinical FI. Methods We used data from a single‐center prospective cohort of adult patients with SLE whose baseline visit ...
Grace Burns, Samuel D. Searle, Alexandra Legge   +2 more
wiley   +1 more source

Mixed-Effects Tobit Joint Models for Longitudinal Data with Skewness, Detection Limits, and Measurement Errors

Journal of Probability and Statistics, 2012
Complex longitudinal data are commonly analyzed using nonlinear mixed-effects (NLME) models with a normal distribution. However, a departure from normality may lead to invalid inference and unreasonable parameter estimates.
Getachew A. Dagne, Yangxin Huang
doaj   +1 more source

Biopsychosocial Determinants of Hand Function and Its Trajectories Over Five Years in Patients With Hand Osteoarthritis

Arthritis Care &Research, EarlyView.
Objective This study aimed to investigate hand function trajectories over five years in primary hand osteoarthritis (OA). Additionally, determinants of baseline and longitudinal hand function were assessed. Methods A total of 538 patients with both baseline and five‐year study visits were analyzed.
Annemiek V. E. M. Olde Meule, Coen van der Meulen, Jos Runhaar, Frits R. Rosendaal, Margreet Kloppenburg   +4 more
wiley   +1 more source

EMMIXuskew: An R Package for Fitting Mixtures of Multivariate Skew t Distributions via the EM Algorithm

Journal of Statistical Software, 2013
This paper describes an algorithm for fitting finite mixtures of unrestricted Multivariate Skew t (FM-uMST) distributions. The package EMMIXuskew implements a closed-form expectation-maximization (EM) algorithm for computing the maximum likelihood (ML ...
Geoff McLachlan, Sharon X Lee
doaj   +1 more source

Joint regression modeling of location and scale parameters of the skew t distribution with application in soil chemistry data. [PDF]

J Appl Stat, 2022
Prataviera F, Batista AM, Libardi PL, Cordeiro GM, Ortega EMM.   +4 more
europepmc   +1 more source

Perceived Impacts and Predictors of Cannabis Products Used by Patients with Rheumatologic Conditions in Alberta, Canada: A Multivariable Analysis of Cross‐Sectional Survey Data

Arthritis Care &Research, EarlyView.
Objective This study aimed to characterize cannabis product choices (cannabinoid content and formulation) among patients with rheumatologic conditions and their associations with patient factors, patient‐reported perceived side effects, and positive impacts.
Susan Zhang, Samuel A.J. Lowe, Frank Sun, Allyson Jones, Tarek Turk, Joanne Olson, Pauline Paul, Shelby Yamamoto, Linda Kolewaski, Elaine Yacyshyn, Cheryl A. Sadowski   +10 more
wiley   +1 more source

A New Goodness-of-Fit Test for Azzalini’s Skew-t Distribution Based on the Energy Distance Framework with Applications

Mathematics
In response to the growing need for flexible parametric models for skewed and heavy-tailed data, this paper introduces a novel goodness-of-fit test for the Skew-t distribution, a widely used flexible parametric probability distribution.
Joseph Njuki, Abeer M. Hasan
doaj   +1 more source

Rheumatoid Arthritis and Coronary Artery Calcium Progression: A Case Cohort Analysis From ELSA‐Brasil

Arthritis Care &Research, EarlyView.
Objective To investigate the association between rheumatoid arthritis (RA) and coronary artery calcium (CAC) prevalence, incidence, and progression over four years in adults without prior cardiovascular disease. Methods A case‐cohort study within the Brazilian Longitudinal Study of Adult Health (ELSA‐Brasil) included 585 participants (86 patients with ...
Patrícia Fonseca Estrada, Marcos Rafael N. Cavalcante, Itamar de Souza Santos, Márcio S. Bittencourt, Vandrize Meneghini, Paulo A. Lotufo, Alessandra C. Goulart, Isabela M. Bensenor   +7 more
wiley   +1 more source