Titlebook: Observational Studies; Paul R. Rosenbaum Book 19951st edition Springer Science+Business Media New York 1995 Analysis.Bias.Observational St

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Randomized Experiments, only in experiments. This chapter reviews the role of randomization in experiments, and so prepares for discussion of observational studies in later chapters. A theory of observational studies must have a clear view of the role of randomization, so it can have an equally clear view of the consequen

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Overt Bias in Observational Studies,t bias is one that can be seen in the data at hand for instance, prior to treatment, treated subjects are observed to have lower incomes than controls. A hidden bias is similar but cannot be seen because the required information was not observed or recorded. Overt biases are controlled using adjustm

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Sensitivity to Hidden Bias,per is a survey of the evidence available in 1959 linking smoking with lung cancer. The paper asks whether the association between smoking and lung cancer is an effect caused by smoking or whether it is instead due to a hidden bias. Can lung cancer be prevented by not smoking? Or are the higher rate

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Known Effects,arction in §4.4.5 is sensitive to small biases while the studies of smoking and lung cancer in §4.3.3 or DES and vaginal cancer in §4.4.5 are sensitive only to biases that are many times larger. If sensitive to small biases, a study is especially open to the criticism that a particular unrecorded co

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Multiple Control Groups,periment, every control is denied the treatment for the same reason, namely, the toss of a coin. In an observational study, there may be several distinct ways that the treatment is denied to a subject. If these several control groups have outcomes that differ substantially and significantly, then th

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Coherence and Focused Hypotheses,ence of the association.” A single sentence defines coherence (Bayne-Jones et al. 1964, p. 185): “A final criterion for the appraisal of causal significance of an association is its coherence with known facts in the natural history and biology of the disease.” There follows a long discussion of the

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Some Strategic Issues,r with supporting theory. Here, correct and effective refer to formal properties of the designs and methods. The first nine chapters discussed issues of this sort. In contrast, a strategic issue concerns the impact that an empirical investigation has on its intended audience. Often, the audience is

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