<prompt> Which of the following is false about Longitudinal studies?Helps us study natural history of a diseaseHelps in identification of risk factor of a diseaseHelps us find out rate of occurrence of new cases of a diseaseEasy to organize and less time consuming  <response>: Longitudinal studies Longitudinal studies are defined as studies having a direction. Longitudinal studies : Helps us study natural history of a disease. Helps in identification of risk factors of a disease. Helps in find out rate of occurrence of new cases of a diseases. Difficult to organize and more time consuming. Includes 1. Coho study :Forward prospective direction; 2 . Case control study :Backward retrospective direction. Veical study Non-longitudinal study : Include cross-sectional study aka snapshot prevalence study , Ecological study aka co-relational study. 