Question: Which of the following is true about risk (or incidence) cohort studies and prognostic cohort studies? Group of answer choices Prognostic cohort studies start with healthy subjects and follow them forward in time to assess risk or incidence of disease Risk (incidence) cohort studies start with healthy subjects and follow them forward in time to assess risk or incidence of disease Prognostic cohort studies are designed to identify risk factors for disease onset Risk (incidence) cohort studies are designed to identify factors that are associated with either positive or negative outcomes.