Surrogate Measures and Consistent Surrogates

Surrogate measures and consistent surrogates.

Surrogates which allow one to predict the effect of the treatment on the outcome of interest from the effect of the treatment on the surrogate are of importance when it is difficult or expensive to measure the primary outcome. Unfortunately, the use of such surrogates can give rise to paradoxical situations in which the effect of the treatment on the surrogate is positive, the surrogate and out...

Surrogate-Based Hypothesis Test without Surrogates

Fourier surrogate data are artificially generated time series, that — based on a resampling scheme — share the linear properties with an observed time series. In this paper we study a statistical surrogate hypothesis test to detect deviations from a linear Gaussian process with respect to asymmetry in time (Q-statistic). We apply this test to a Fourier representable function and obtain a repres...

Surrogate measures of arterial stiffness: do they have additive predictive value or are they only surrogates of a surrogate?

Recent epidemiological studies have shown that arterial stiffness, measured through carotid-femoral pulse wave velocity (PWV), has an independent predictive value for cardiovascular (CV) events in several populations, including patients with uncomplicated essential hypertension1,2 and type 2 diabetes.3 Arterial stiffness is thus an intermediate end point for CV events, predicting CV events inde...

Estimating Treatment Effects using Multiple Surrogates : The Role of the Surrogate Score and the Surrogate Index

Estimating the long-term effects of treatments is of interest in many fields. A common challenge in estimating such treatment effects is that long-term outcomes are unobserved in the time frame needed to make policy decisions. One approach to overcome this missing data problem is to analyze treatments effects on an intermediate outcome, often called a statistical surrogate, if it satisfies the ...

Surrogate Measures of Safety