89. TRUE/FALSE. In a crossover design, participants may be switched among treatment groups.
90. TRUE/FALSE. Both confounding variables and effect modifiers are controlled in the same way. 91. TRUE/FALSE. Randomization only controls for known confounders. 92. TRUE/FALSE. Phase 11 triais test how the body responds to a drug or treatment. 93. TRUE/FALSE. The Tuskegee Study exemplified a research project that violated ethical standards for research. Match the study description with the appropriate study design. Fach study design may be used once, more than once, or not at all, STUDY STRENGTH 94. Eligible participants are randomly assigned to one of four groups. The groups represent the different combinations of the two interventions. 95. All participants are initially placed on a placebo. Those who remain after a short: series period of time are then randomly assigned to either the placebo or treatment arm the study, 96. The outcome variables are measured at baseline, then the intervention is applied to the whole cohort. The outcome variables are measured again at the end of the follow-up period. 97. Participants are randomized to treatment or placebo and outcome variables are measured. A washout period occurs to reduce carryover effect. Then the placebo group is assigned to the intervention and vice versa; outcome variables are again measured.
STUDY DESIGN
A. Time series
B. Crossover
C. Run-in
D. Factorial