Assignment #2 STAT 6510 Biostatistical Methods Due Nov 2, 2020 1. Give an example of a randomized clinical trial for which blinding of the treatments would not be possible and indicate why blinding is not possible. 2. A trial of two drugs, pyrimethamine and clindamycin, for the prevention of toxoplasmosisncephalitis (TE) is planned. Clindamycin and pyrimethamine could not be made to look alike, but placebo could be prepared to match each drug. Thus, the investigators proposed a partially blinded placebo-controlled study in which one-half of the patients were to be randomized to pyrimethamine or matching placebo in a 2:1 allocation (250 receive active treatment and 125 placebo). The remaining half of the patients would be randomized to clindamycin or matching placebo in a 2:1 allocation ratio. Patients and clinicians would know if they are in the clindamycin or pyrimethamine arm but would not know whether they were taking active drug or placebo. After this study design was reviewed, the sponsor requested that the study be fully blinded (double-blind) so that comparisons of active clindamycin and active pyrimethamine would be blinded. Assume patients are to take one 25 mg tablet of pyrimethamine (or matching placebo) by mouth 3 times/week (Monday, Wednesday and Friday), or one 300 my tablet of clindamycin (or matching placebo) by mouth twice every day (morning and evening). Describe how you would package and distribute the medication to patients in order to conduct the study double-blind. Keep in mind that clindamycin and pyrimethamine can not be made to look alike