A Fundamental Equivalence between Randomized Experiments and Observational Studies

Covariance Adjustment in Randomized Experiments and Observational Studies

By slightly reframing the concept of covariance adjustment in randomized experiments, a method of exact permutation inference is derived that is entirely free of distributional assumptions and uses the random assignment of treatments as the “reasoned basis for inference.” This method of exact permutation inference may be used with many forms of covariance adjustment, including robust regression...

Attributable E¤ects in Randomized Experiments and Observational Studies

The motivation for randomization inference and sensitivity analysis is reviewed. New methods are discussed for inverting randomization tests to provide interval estimates of the magnitude of treatment e¤ects. 1 Notation and Review

Randomized Experiments and Observational Studies: Causal Inference in Statistics

This talk describes the theory of causal inference in randomized experiments and nonrandomized observational studies, using two simple theoretical/actual examples for illustration. Key ideas: causal effects, randomized experiments, adjustments for observed covariates, sensitivity analysis for unobserved covariates, reducing sensitivity to hidden bias using design strategies. 1. Seven Key Contri...

Confounding Equivalence in Observational Studies

Evidence gathered from randomized clinical trials and observational studies on the equivalence of emtricitabine and Lamivudine.

TO THE EDITOR—We read the commentary by Ford et al on our study regarding the comparability of results from trials and cohorts regarding the efficacy of lamivudine (3TC) and emtricitabine (FTC) in combination antiretroviral therapy (ART) [1, 2]. Of course, we can only agree with the statement that evidence from randomized clinical trials (RCTs) is of higher quality than observational studies. B...