Natural history of a disease is studied with: (A) Longitudinal studies, (B) Cross sectional studies, (C) Randomized control trials, (D) Randomized sampling
Answer is A. Longitudinal studies are in which observations are repeated in the same population over a prolonged period of time by means of follow-up examination. They are useful in1) to study the natural history of the disease and its future outcome2) for identifying risk factors for disease3) For finding out incidence rate or rate of occurrence of new cases of a disease in the community.Park 23e pg: 70