A typical approach in surrogate-based modeling is to assess the performance of alternative surrogate models and select the model that performs the best. In this paper, we extend the utility of an ensemble of surrogates to: i) identify regions of high uncertainties at locations where predictions of surrogates widely differ, and ii) provide a more robust approximation approach. We explore the pos...

Prentice [1] offered a statistical definition of a surrogate endpoint as ‘a response variable for which a test of the null hypothesis of no relationship to the treatment groups under comparison is also a valid test of the corresponding null hypothesis based on the true endpoint’. A National Institutes of Health (NIH) working group generated less quantitatively rigorous definitions that contrast...

Drinking and driving has been the subject of considerable public concern and legislative attention in many countries in recent years. In Canada, the federal criminal laws and provincial traYc acts have been significantly amended since the mid-1980s: police investigatory powers have been broadened, new federal crimes and provincial oVences have been enacted, and more onerous penalties and admini...

Mothers Against Drunk Driving (MADD) has arguably been one of the most successful public-health grassroots citizen advocacy organizations in the United States in the past century. In 2005, MADD celebrated the 25th anniversary of its founding. Based on a national poll by the Gallup Organization in 2005, MADD is recognized by 94% of citizens. It is generally given credit for changing American att...

The objective of this study is to develop an accurate surrogate modeling method for construction of the surrogate model to represent the performance measures of the compute-intensive simulation model in reliability-based design optimization (RBDO). In addition, an assessment method for the confidence level of the surrogate model and a conservative surrogate model to account the uncertainty of t...

OBJECTIVES To explore the use of surrogate outcomes in Health Technology Assessment (HTA) and provide a basis for guidance for their future use, validation and reporting. This report focuses on the role of surrogate outcomes in cost-effectiveness models (CEMs) within UK HTA Programme reports. DATA SOURCES Reports published in the UK HTA Programme monograph series in 2005 and 2006 formed the s...

OBJECTIVE To assess if authors of randomised clinical trials convey the fact that they have used surrogate outcomes and discussed their validity. DESIGN Cohort study. SETTING Six major general medical journals. PARTICIPANTS Randomised clinical trials published in 2005 and 2006 that used a surrogate as a primary outcome. RESULTS Of 626 published randomised clinical trials, 109 (17%) used...

We study surrogate losses in the context of cost-sensitive classification with example-dependent costs, a problem also known as regression level set estimation. We give sufficient conditions on the surrogate loss for the existence of a surrogate regret bound. Such bounds imply that as the surrogate risk tends to its optimal value, so too does the expected misclassification cost. These kinds of ...

BACKGROUND Polycystic ovary syndrome (PCOS), whose aetiology is unknown, is predominately a familial syndrome but confirmation of candidate genes has proved elusive. The developmental hypothesis for the origin of PCOS suggests that exposure of the fetus to excess androgens influences imprinting, leading to altered genetic expression in adult life. The aim of this pilot study was to examine whet...