ABSTRACT
Clinical experiments have evolved for many hundreds of years. The current state-of-theart clinical experiment is the randomized, controlled clinical trial. These advanced experiments have been used to demonstrate important relationships in public health. Two examples are 1) the association between reductions in elevated levels of blood pressure and the reduced incidence of strokes, and 2) the reduction of blood cholesterol levels and the reduced occurrence of heart attacks. However, many patients who agree to participate in this trial often choose not to return to the clinical trial physician for regularly scheduled followup visits. Although this behavior is understandable, and is in no way unethical, the absence of these patients from all future participation in the trial can complicate the interpretation of the trial. After a brief introduction to clinical trials, this chapter will apply difference equation methodology to predictions about the frequency of these required patient visits that would be useful to clinical trial workers.
