Cross-sectional studies arise by selecting a study population at a particular point in time. This study is designed to show the prevalence of certain characteristics and diseases in a population. In many instances, cross-sectional studies can be useful to identify numbers of patients who might be eligible for particular types of services at a medical institution. Cross-sectional designs are not as frequently used as case-control studies or cohort studies, which are the primary mechanisms to identify risk factors for particular diseases.