# 1. A drug is being tested in a chronic disease whose condition waxes and wanes over time. Which of the following study designs is most effective in evaluating the efficacy and safety of a new therapy for this disease? A. Retrospective Cohort B. Case-Control C. Prospective, Randomized, Active Control, Parallel Group Design D. Prospective, Randomized, Active Control, Crossover Design

Question
Study design
1. A drug is being tested in a chronic disease whose condition waxes and wanes over time. Which of the following study designs is most effective in evaluating the efficacy and safety of a new therapy
for this disease?
A. Retrospective Cohort
B. Case-Control
C. Prospective, Randomized, Active Control, Parallel Group Design
D. Prospective, Randomized, Active Control, Crossover Design

2021-03-08
Step 1
There are many different type of studies and different ways of their conduction.
For each of these type of studies,there are crucial features to look for in study design.
Step 2
For studies testing if new interventions are effective it not,most reliable design would be a randomized comparative trial.
In this trial,patients on which studies are going on,are allocated by chance to either the new interventions that is being tested,or the alternative comparative treatment.
Sometimes, comparative treatment is a kind of placebo drug or procedure or sometimes the best treatment available.
Step 3
For testing efficacy of drug treatment, surgical procedure: preferred design is randomized controlled trial
For diagnosis: Combination of randomized comparison of new test with old follow up of cohort
For screening : longitudinal cohort study of patient with Disease
For prognosis: longitudinal cohort study of patient
Causation:case control or cohort study
Step 4
So keeping all the points in mind
Correct option will be
D. Prospective, Randomized, Active Control, Crossover Design

### Relevant Questions

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