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 first approach involves measuring a surrogate variable of operating risk, and the second approach involves an analysis of fixed costs that provides a surrogate Beta risk measure for the Capital Asset Pricing Model (CAPM) computation of cost of capital.
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.
Regardless of the origins of association rule learning, and notwithstanding the considerable difficulties in mining natural language text, in the 1980s McCormack Pharma pioneered the use of antecedent surrogate variables in association rules learning before such methods were widely used or even understood; moreover, at that time the field of text mining was barely nascent.
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].
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.