SAS Macros for Fitting Multivariate Measurement Error Models and Estimating Multivariate Usual Intake Distributions
ثبت نشده
چکیده
For dietary surveillance in the United States, the preferred method for collecting dietary intake data is the 24-hour dietary recall. However, researchers are interested in usual intake (i.e. long-term average daily intake). Researchers are also interested in exploring multiple dietary components collectively to consider dietary patterns, and consumption of these dietary components varies. Some dietary components are consumed almost daily by almost everyone and other dietary components are consumed episodically.
منابع مشابه
IRT-FIT: SAS® Macros for Fitting Item Response Theory (IRT) Models
Psychometrics has recently seen the development of complex measurement models to better represent test and item data. Item Response Theory (IRT), in particular, comprises a set of non-linear latent variable models that appear to have several conceptual and empirical properties that make them more valuable in practice than classical test theory methods. However, IRT-based models typically requir...
متن کاملFitting a bivariate measurement error model for episodically consumed dietary components.
There has been great public health interest in estimating usual, i.e., long-term average, intake of episodically consumed dietary components that are not consumed daily by everyone, e.g., fish, red meat and whole grains. Short-term measurements of episodically consumed dietary components have zero-inflated skewed distributions. So-called two-part models have been developed for such data in orde...
متن کاملEstimating the Distribution of Dietary Consumption Patterns.
In the United States the preferred method of obtaining dietary intake data is the 24-hour dietary recall, yet the measure of most interest is usual or long-term average daily intake, which is impossible to measure. Thus, usual dietary intake is assessed with considerable measurement error. We were interested in estimating the population distribution of the Healthy Eating Index-2005 (HEI-2005), ...
متن کاملQuantifying and Testing Indirect Effects in Simple Mediation Models When the Constituent Paths Are Nonlinear.
Most treatments of indirect effects and mediation in the statistical methods literature and the corresponding methods used by behavioral scientists have assumed linear relationships between variables in the causal system. Here we describe and extend a method first introduced by Stolzenberg (1980) for estimating indirect effects in models of mediators and outcomes that are nonlinear functions bu...
متن کاملLIRT: SAS macros for longitudinal IRT models
Item response theory models are often applied when a number items are used to measure a unidimensional latent variable. Originally proposed within educational research, they are now also being used when focus is on e.g. physical functioning or psychological well-being. Modern applications often need more general models, typically models for multidimensional latent variables or longitudinal mode...
متن کامل