Which one of the following statements is/are true or false regarding cohort and case-control studies? (I) Case-control studies are controlled experiments, whilst cohort studies are observational studies. (II) Case-control studies are better for rare diseases, compared to cohort studies.

Step 1 Result and Explanation:
(i) Observational Studies: Observational studies are an important category of study designs. To address some investigative questions in surgeries, randomized controlled experiments are not always indicated or ethical to conduct. instead, observational studies may be the best method to address these types of questions. Cohort studies and Case-control studies are two primary types of observational studies that are evaluating associations between diseases and exposures. Observational studies fall under the category of analytical study designs and are further sub-classified as observational or experimental study designs. Case control studies and cohort studies offers specific advantages by measuring disease occurrence. Case-control studies are controlled experiments, whilst cohort studies are observational studies is true regarding cohort and case-control studies.
Step 2 Result and Explanation:
(ii) Case-control studies are better for rare diseases, compared to cohort studies. It is true because they do not require a long follow-up period means as the disease has already developed and are hence much cheaper. It is also very suitable for diseases with a long period such as cancer. However, case-control studies are less adept at showing a casual relationship than cohort studies and there are more prone to bias. Cohort studies are not same as case-control studies, the exposure and outcomes have already happened.