Question
The following statements all apply to experimental studies. State whether they are true or false. If false, provide a reason.
a. A treatment group always needs to be compared with a placebo group, to account for feelings of well-being associated simply with being treated.
b. A key aspect of blinding (masking) is preventing an investigator from making their own decisions about what is the best treatment for the patient.
c. A blocked randomized design is most useful if the sample size is small.
d. An intention-to-treat analysis is the most appropriate method of evaluating the efficacy of the treatment.
e. In a factorial design study, each participant is assigned to each treatment at a different time.
f. It would be unethical to continue with an experimental study if a mid-point analysis shows a clear benefit of the treatment.
g. The main analysis in a prevention trial compares the incidence of the outcome in the groups being compared, never having to adjust for other factors, because of the randomization process.
h. Prevention trials usually require fewer participants than treatment trials.
i. Stratified randomization can be used to ensure sufficient members of minority groups are included in a study.
j. Assume that there is no existing knowledge about this issue. A randomized study allocating people to two groups, one using sunbeds (tanning beds) and the other not using sunbeds, would be an efficient way to find out whether these beds really are associated with skin cancer.
k. A goal of randomization in experimental studies is to ensure equipoise.
l. Having a large study population ensures equal sample size in the randomized groups of an experimental study.
