Question

What type of analytical study would a modern-day epidemiologist carry out to determine whether or not exposures actually do increase the risk of particular diseases?

Answer 1

Analytical studies are done in order to find out if an outcome is related to exposure. There are four main types of analytical studies- cross-sectional being one of them.

They measure:

1. Prevalence of exposure together with
2. Prevalence of disease

Information on exposures and disease status are obtained at the same point in time, therefore these studies involve data collection at a defined time. These studies are easy to be conducted and are quick and relatively cheap. They are often used where there is no registry of disease, for example studies of respiratory disease or national health surveys. Cross-sectional studies measure prevalence, not incidence of disease. Temporal sequence of exposure and effect maybe difficult or even impossible to determine. They differ from case-control studies in that they aim to provide data on the entire population under study, whereas case-control studies typically include only individuals with a specific characteristic, with a sample, often a tiny minority, of the rest of the population. Unlike case-control studies, they can be used to describe absolute risks and not only relative risks.