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”> 27 Matching in Observational Studies In Sections 25.4 and 26.3.1 we described the use of multiple cohorts and multiple control groups, respectively. For cohort studies, cohort…
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”> 26 Participants in Case-Control Studies Case-control studies are designed to assess whether there is a link between one or more exposures and a particular outcome. 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”> 25 Defining Populations for Cohort Studies Chapter 6 presented an overview of cohort studies, which are observational studies of the relationship between exposures and outcomes 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”> 24 Adherence and Compliance You, the investigator, want the participants to comply with your study procedures, which involves coming back for study visits as scheduled and…
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….
