html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 23 Techniques to Blind Interventional Studies In the previous chapter we described the purpose of blinding and the different levels used. In this chapter we describe…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 22 Blinding in Interventional Studies Many measurements in clinical studies have a subjective component that may be influenced by knowledge of the participant’s treatment. Blinding, also…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 21 Techniques for Randomization In this chapter we describe methods for creating a randomization schedule for interventional studies. The definition, rationale, and importance of randomization are…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 20 Randomization: What and Why Einstein is often thought to have said that “God does not play dice with the universe.” Without entering either in the…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 19 Describing the Intervention It might seem easy to define the intervention you want to study, but it rarely is. Although you know what the intervention…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 17 Bias Bias is the single biggest potential problem in clinical research. Bias means that the results observed are consistently influenced away from the true result….
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 18 Avoiding Bias This book is about creating a valid study, and a study must be unbiased to be valid, so in some sense this whole…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 16 Study Data: Predictor and Confounding Variables In this chapter we discuss predictor and confounding variables, two categories of variables that are assumed to influence the…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 15 Study Data: Endpoints In this chapter we discuss the outcome variables, which are the endpoints of a study. These are the most critical measurements in…
html xmlns=”http://www.w3.org/1999/xhtml” xmlns:mml=”http://www.w3.org/1998/Math/MathML” xmlns:epub=”http://www.idpf.org/2007/ops”> 14 Study Data: How Variables Are Used A study is about information. Information is obtained from data. Investigators collect data, examine this data, describe the values…
