To describe representativeness, the study population must be compared with the target population. The target population is the population that a study is supposed to make scientific statements about. An intersectional perspective enables the disclosure of complex patterns of representativeness for all intersections of a society and can reveal the extent to which societal diversity is represented in study populations. When describing the representativeness of a study, intersections of different social categories should therefore be made visible.

The PROGRESS Plus framework can support the selection of social categories for describing the representativeness of a study from an intersectional perspective. Social categories should be combined to form intersections. Frequencies of the intersections thus formed can then be compared between the study population and the target population. 

Information about the target population can be obtained from representative surveys such as a census or microcensus. If certain information is not available in the census data, non-participants can be interviewed through a non-responder survey .

Furthermore, intersectionality-informed statistical methods are available to implement an intersectional perspective in the quantitative analysis of representativeness.

In order to describe representativeness in research, relevant variables must first be defined based on theoretical considerations. The theoretical concept of intersectionality can support this selection. In particular, an intersectional perspective can assess the potential for bias in measures of morbidity. Since categories of difference such as socioeconomic status, ethnicity or gender are associated with morbidity, these measures would be distorted if individual ethnic groups or sexes/genders were under- or over-represented.

An intersectional perspective can also reveal the representativeness of vulnerable populations in research. On the one hand, vulnerable populations should be protected from burdens or risks that may arise from studies and thus should not be unjustifiably overrepresented. On the other hand, vulnerable populations should not be underrepresented, as this would hinder reliably determining health resources and risks in these populations. 

Findings on a study’s representativeness can ultimately be used to improve opportunities for all members of society to participate in research in the future.

The concept of intersectionality does not cover all factors that are relevant to describe the representativeness of a study. Other characteristics associated with study participation and disease risks such as tobacco use or subjective health should also be considered.

In some studies, there may be too few observations at certain intersections to obtain meaningful results on their representativeness. Finally, in practice, it is often difficult to obtain information on non-participants.