surrogate variable

surrogate variable

A variable in a clinical trial that provides an indirect measure of efficacy in situations where direct measure of a clinical effect is not possible or practical.
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This simple manipulation of the lighting and equipment typical load shapes, which reflects the strong correlation between the occupancy and the lighting and equipment loads, produced profiles reasonably similar to the occupancy profiles obtained by the walk-through survey, which suggests accepting the results of a surrogate variable for the true occupancy variable.
The best available surrogate variable was selected for the replication model when the variables in the model were not exactly duplicatable.
The surrogate variables used to replicate LRL's analysis may not have captured price variance as well as their original variables.
separating relevant from irrelevant predictors; -- transforming predictors exhibiting nonlinear relationships with the target variable; -- determining interactions between predictors; -- handling missing values with new surrogate variable techniques; and -- conducting self-validation tests to ensure the model holds up to new data.
The latter was deemed as not fully feasible within the scope of this call and our decision was to test the most relevant approaches (diet, exercise, vitamin D, alone or in combination) against surrogate variables of GDM (fasting blood glucose, insulin sensitivity, pregnancy weight gain) to come up with the best intervention for entry into a definitive GDM prevention trial.
d) Maximization of the Lagrangian with respect to the new surrogate variables y (say) leads to the set of equations which determine the lagrangian parameter [beta].
o], we upgrade their values step by step and find the corresponding values of the surrogate variables [y.
Current exposure to TNF inhibitors, as monotherapy or in combination with methotrexate or other DMARDs, was compared with methotrexate monotherapy, and all analyses were adjusted for multiple potentially confounding risk factors including surrogate variables for smoking and dyslipidemia.
Population density and land use data was also used as surrogate variables to quantify contaminant loading.
Soil subgroup, site type, depth of O horizon, depth of A horizon and number of fallen dead trees were chosen as surrogate variables for nutrient availability.
Clearly, surrogate variables are needed in some instances, and clearly they have been used well in several studies.