. 2012 Aug 8;3:145. doi: 10.3389/fgene.2012.00145

Table 1.

Description of designs given to study participants.

Design	Description
Study A – single randomization design	In study A, the classic design, if you were to participate you would be randomly assigned to take either the active drug being studied or to a pill with no drug (a placebo). There would be a 50% chance that you will be assigned to take the placebo. The study would be run “double blind” so that neither you nor the study staff would know whether you are taking the active drug or the placebo until after the study is over. The study will proceed like this for 24 months (2 years), and every month you would be asked to come to the clinic and be weighed.
Study B – repeated randomization design	In study B, a new design, if you were to participate, you would be randomly assigned each month to the active drug being studied or to a placebo. You would be assigned to the active drug or placebo an equal number of times; that is, you would be guaranteed to get the drug for 12 of the 24 months in random order. The study will be run “double blind” so that neither you nor the study staff will know whether you are taking the active drug or the placebo during any particular month. The study will proceed like this for 24 months (2 years), and every month you would be asked to come to the clinic and be weighed.

Design

Description

Study A – single randomization design

In study A, the classic design, if you were to participate you would be randomly assigned to take either the active drug being studied or to a pill with no drug (a placebo). There would be a 50% chance that you will be assigned to take the placebo. The study would be run “double blind” so that neither you nor the study staff would know whether you are taking the active drug or the placebo until after the study is over. The study will proceed like this for 24 months (2 years), and every month you would be asked to come to the clinic and be weighed.

Study B – repeated randomization design

In study B, a new design, if you were to participate, you would be randomly assigned each month to the active drug being studied or to a placebo. You would be assigned to the active drug or placebo an equal number of times; that is, you would be guaranteed to get the drug for 12 of the 24 months in random order. The study will be run “double blind” so that neither you nor the study staff will know whether you are taking the active drug or the placebo during any particular month. The study will proceed like this for 24 months (2 years), and every month you would be asked to come to the clinic and be weighed.