Search results for "Polytomous Rasch model"
showing 7 items of 7 documents
Diagnostic delay in oral squamous cell carcinoma: the role of cognitive and psychological variables
2014
This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age: 62 years, M/F: 2.39∶1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included: sociodemographic, health-related, cognitive and psychological variables. The analysis was conducted by considering two different delay ranges: dichotomous (≤1 month vs. >1 month) and polytomous (3 months) delay. Data were investigated…
Rasch scalability of the somatosensory amplification scale: a mixture distribution approach.
2012
Abstract Objective Somatosensory amplification refers to a person's tendency to experience somatic sensations as inappropriately intense and involves hypervigilance concerning bodily sensations. We applied the Somatosensory Amplification Scale (SSAS) in an Internet sample of young adults (N = 3031) to test whether the SSAS is Rasch scalable. Methods We applied mixture distribution extensions of the partial credit and rating scale models to identify possible subgroups that use the response set of the SSAS in different ways. Results A partial credit model, with two latent classes, showed a superior fit to all other models. Still, one of the SSAS items had to be removed because it showed sever…
Dimensionality of depression in acute schizophrenia: a methodological study using the Bech-Rafaelsen Melancholia Scale (BRMES).
1998
Abstract Despite the great clinical importance of depressive symptoms in schizophrenia there is a lack of studies on the assessment and evaluation of depression in acutely psychotic patients. For the Bech-Rafaelsen Melancholia Scale (BRMES), among other advantages, the concept of unidimensionality was confirmed in patients with major depression by different methodological approaches including Rasch analysis. The present evaluation was designed to investigate the scale properties of the BRMES in acutely schizophrenic patients with particular emphasis on the dimensionality of the scale. Three different statistical approaches were used: principal component analysis in combination with computer…
Rasch measurement in educational contexts Special issue 1: Rasch modeling in educational testing
2011
This is the first of two special journal issues on Rasch measurement in educational contexts. Most of the articles compiled in these two issues originate from a symposium of the same title held in ...
Advantages of the Rasch measurement model in analysing educational tests:an applicator's reflection
2011
Educational achievement is a very important issue for parents, teachers, and the government. An accurate measurement plays a very important role in evaluating achievement fairly, and, therefore, analysis methods have been developed considerably in recent years. Education based on long-time learning processes forms a fruitful base for item tests, as it opens up possibilities to design a nearly unlimited number of items. There are several methods available to analyse such tests, but which method is the most useful and in which situation? The Rasch measurement from the Institute for Object Measurement (IOM) has pointed out to be the most useful in evaluating individual items and their function…
Estimating person parameters via item response model and simple sum score in small samples with few polytomous items: A simulation study
2018
Background The Item Response Theory (IRT) is becoming increasingly popular for item analysis. Theoretical considerations and simulation studies suggest that parameter estimates will become precise only by utilizing many items in large samples. Method A simulation study focusing on a single scale was performed on data with (a) n = 40, 60, 80, 120, 200, 300, 500, and 900 cases utilizing (b) 4, 8, 16, or 32 items. The items were (c) symmetrically distributed vs. skew (skewness 0, 1, and 2). Item loadings were (d) homogeneous vs. heterogeneous. Item loadings were (e) low vs. high. Half of the items had (f) a correlated error or not. The number of answering categories (g) was four vs. five. A to…
The development of a short measure of physical function for knee OA KOOS-Physical Function Shortform (KOOS-PS) – an OARSI/OMERACT initiative
2008
Udgivelsesdato: maj OBJECTIVE: To develop a short measure of physical function for knee osteoarthritis (OA) using multi-national data from individuals with varying degrees of severity of knee OA. METHODS: Rasch analysis, based on the partial credit model, was conducted on Knee injury and Osteoarthritis Outcome Score and Western Ontario McMaster Universities' Osteoarthritis Index data from individuals with knee OA, ranging from community to pre-total knee replacement samples from five countries. Fit of the data to the Rasch model was evaluated by overall model fit and item-level fit statistics (chi(2), size of residual, F-test). Invariance across age, gender and country was evaluated. Unidim…