Question

Which of the following study designs is best suited for assessing an exposure-disease relationship when the disease is rare? [Choose the ONE best answer): A Cross-sectional B. Case-control C. Retrospective cohort D. Prospective cohort

Answer 1

Option C. Case control Design is best suited for assessing an exposure-disease relationshio when the disease is rare.

Explanation : The main thing about rare diseases is that its "rare". In other forms of study like cross-sectional or retrospective , even if we choose very large sample , it might be the case that we don't have enough people having the disease. So, in case control study we can select a sufficient number of people having this rare disease and then set up a particular number of control people. Then, we can study the exposure factor in retrospect and see whether it has any effect on the disease. Prospective study isn't possible because in case of rare diseases we may not know the time of advent of the disease, hence it may be futile.