Cross-sectional study

In epidemiology, cross-sectional studies are "studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with longitudinal studies which are followed over a period of time."

Cross sectional studies are relatively easy to execute because there is no need to wait for a health outcome to occur or estimate levels of exposure to risk factors in the past. Their main disadvantage is that a specific cause can't be easily inferred, because only current health and exposure are being studied.