Question

the difference between a cross-sectional study, prospective study, and retrospective study

Answer 1

Difference:
Cross-sectional study:
It is a type of observational study for analysis population data at a specific point of time.
Example: Looking at the prevalence of HIV within the population.
Prospective study:
It evaluates the outcome with the study period and factors associated with risk, it is a cohort subject study evaluating a subject over a long period.
Example: Particular race, age developing with the particular disease over the period of time and it identifies the factors for their risk.
Retrospective study:
It evaluates previous sources and examines the risk factors for the outcome, it compares two groups of people with the same disease condition.
Example: One group of people exposed to a particular substance that another group was not but affected by the same disease condition.