Background

There is a growing awareness of the need to integrate sex and gender adequately into health-related research [1,2,3,4,5]. For appropriate integration to be successful, the definitions of sex and gender, their multidimensionality and their underlying concepts must be known and applied correctly [6]. In the concepts currently discussed in health-related research, the term sex as a multidimensional biological construct refers to attributes such as anatomy, physiology, genes and hormones and is usually operationalised as female, male or intersex [2, 5,6,7]. Gender as a multidimensional social construct refers to roles, behaviours, relationships, power relations and other aspects that are usually socially associated with certain gender identities [2, 6, 7]. Thus, gender does not only act on an individual but on a structural and symbolic level as well [8] (see glossary). Both the sex-linked biology and gender refer to multiple dimensions that are entangled but, however, not mutually dependent [2, 9]. The variety of sex/gender cannot be accurately captured by a dichotomous understanding of male/female. Thus, there is a need for new approaches that adequately capture this complexity of sex/gender and its diversity beyond binary categories [3, 9,10,11]. To highlight the entanglement of sex and gender, we use the term sex/gender for a non-binary category, that has multiple, interwoven biological and social dimensions, as it is also conceptualised in the embodiment theory [2, 12, 13] (see glossary). An intersectionality perspective, which means considering the intersection of sex/gender with other social categories (e.g. socioeconomic position, race/ethnicity, sexual orientation) and the associated privileges and oppressions, strengthens the consideration of structural causes of health inequities such as systems of power and discrimination processes [2, 14,15,16,17] (see glossary).

Sex/gender-equitable research profoundly includes the needs of all sex/gender groups throughout the entire research process [3] (see glossary). Adopting an intersectionality perspective enables the recognition, reflection, and consideration of connections and interactions of sex/gender with multiple social categories, power relations, as well as possible discrimination structures and processes and can thus lead to a more sophisticated differentiation of sex/gender groups [2, 15, 18]. Highlighting gendered power relations, norms, roles and stereotypes in research might help to reduce sex/gender discrimination and health-related sex/gender differences resulting from inequities and structural disadvantage [3].

Not all approaches to include sex/gender into health-related research are sex/gender-equitable. Different approaches and their features and methodological requirements can be seen in Fig. 1. A gender-blind approach can contribute to unequal treatment of men and women, while the gender-differentiated approach takes into account sex differences and the gender-sensitive approach additionally considers biological and social factors that lead to health-related differences between sex/gender groups. However, these three approaches cannot remove inequalities between women and men, only the fourth sex/gender-transformative approach leads to equity of all sex/gender groups. Sex/gender transformation aims to address the root causes of sex/gender inequities and works to change harmful gendered power relations, norms, roles and stereotypes [19, 20] (see glossary). There may be further approaches to integrate sex/gender in health-related research that are not explicitly shown in the figure. When using the framework researchers should consider that in practice, extreme or mixed forms of the presented approaches may occur.

Fig. 1
figure 1

Conceptual differences of approaches to take sex/gender into account in quantitative health research [Based on the framework of Pederson et al., 2014, further adapted to epidemiological research]

Full size image

Objective

Although it is widely known that sex/gender is not comprehensively considered in most studies to date [4, 6, 21, 22], current publications of conceptual considerations and guidelines often contain recommendations that refer to individual phases of the research process. To the best of our knowledge, there is lack of detailed guidance that accompanies the adequate consideration of sex/gender concerning multidimensionality, variety, embodiment and intersectionality in each step of the entire research process. So, the aim of this publication is to raise awareness and to provide assistance in form of a checklist that encourages sex/gender transformative research at all stages of the research process, focussing on quantitative health research.

Methods

INGER project

This checklist was developed as part of the collaborative research project INGER (“Integrating gender into environmental health research”). INGER focuses on improving research by integrating sex/gender into environmental health research and thus aims to make it more sex/gender-equitable (https://www.uni-bremen.de/en/inger). As part of the project, systematic reviews were conducted, which showed that sex/gender has not yet been adequately considered in environmental health research [23, 24] and Bolte et al. developed a multidimensional sex/gender concept including intersectionality [2]. Furthermore, an operationalisation of the developed concept was introduced [25] and innovative methods for analysing data on sex/gender in population-based environmental health studies were implemented [26].

Development process

The checklist presented in this publication builds on current guidelines promoting the adequate consideration of sex/gender from an intersectional perspective in health-related research. Starting from three important key documents “Gendered Innovations” [27], “Gendered Innovations 2” [22] and the “SAGER Guidelines” [4], further relevant publications were retrieved. Firstly, we collected publications that are currently consulted within the disciplines involved in INGER (epidemiology, public health, gender studies and psychology). Furthermore, we used a snowball method by searching for further relevant titles in the bibliographies of the publications that were already included. Since our checklist was intended to refer to current approaches, our selection was limited to papers published between 2000 and 2021. We restricted our search to documents written in English or German. The identification of relevant publications was continued until saturation was reached.

55 relevant publications published between 2000 and 2021 were identified and included in the development of this checklist (see supplement). In a first step, recommendations referring to sex/gender consideration in the research process were extracted from these 55 publications, partly using words close to the original text, assigning them to the respective section of all steps of the research process as given below. The collection and review of the publications was carried out by two members of the research team.

Steps of a research process:

  • background assumptions and theory,

  • scientific evidence base,

  • research questions and hypotheses,

  • study design,

  • study population,

  • operationalisation of sex/gender,

  • data collection,

  • data analyses,

  • presentation of results,

  • interpretation/discussion,

  • publication/dissemination,

  • research team,

  • transfer,

  • science and risk communication,

  • avoidance of stereotypes and.

  • language.

In a second step, the contents were summarised in a condensed form, as some publications gave the same or similar recommendations. As the recommendations of previous publications did not cover every step of the research process and often considered sex/gender in a binary way, we filled this research gap in a third step. We modified and enriched the recommendations based on the expertise of the researchers of the INGER study group, aiming to add further categories to the binary sex/gender categories by considering sex/gender from an intersectional perspective. We do not claim that the developed checklist is complete.

Results

The checklist addresses sex/gender aspects of the whole research process of planning, implementing and analysing quantitative health studies as well as aspects of appropriate language, communication of results to the scientific community and the public, and composition of the research team. It comprises 67 sex/gender related items in 15 sections, key points that refer to an intersectional approach to sex/gender were marked (Table 1). A glossary provides a compact overview of the most important terms (Table 2).

Table 1 Comprehensive checklist for the consideration of sex/gender [4, 6, 7, 10, 13, 14, 18, 21, 22, 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72]
Full size table

Discussion

So far, sex/gender has not often been comprehensively considered in health-related research, although it is known that adequate consideration of sex/gender together with potentially interacting social categories such as socioeconomic position, race/ethnicity and sexual orientation promotes scientific quality of the results. This may help to achieve more equity in health-related research in the long term. An adequate consideration of sex/gender can ensure that research results and prevention programs apply to all people in terms of sex/gender and do not only represent a certain part of society [4, 6, 21, 22].

The introduced checklist for the incorporation of sex/gender-related multidimensionality, variety, embodiment and intersectionality into the research process is a compilation of recommendations from 55 publications, identified from relevant publications of several disciplines. Recommendations were not only extracted and summarised, but also modified and enriched based on the interdisciplinary expertise of the authors in order to consider the complexity of sex/gender and go beyond a binary understanding.

Based on profound expert knowledge in the disciplines epidemiology, public health, and gender studies, and an already established collection of pertinent checklists, we selected three key documents for further search of checklists published in the last years. Instead of a systematic literature search in several literature databases with specific keywords, we used the snowball method until saturation in terms of recommendations given in the identified checklists was reached. This approach can be a limitation, because relevant literature might have not been identified in the development of our checklist. A great strength of our checklist is its comprehensiveness as it covers all steps of the research process. In this way, it represents a comprehensive aid for researchers. But at the same time this strength is also a limitation, as our aim of developing a comprehensive checklist has resulted in the final product being very complex. Thus, the presented items may not all be self-explanatory. In order to adequately use it, it might be necessary to include experts from the field of sex/gender research into the whole research process or to improve the sex/gender knowledge of members of the research team.

Although the INGER project focused on environmental health research, no aspects that were specific to this research area were identified in the checklist. To follow the recommendations given for evaluating the current scientific evidence base, further approaches of INGER, such as the sex/gender-focused systematic reviews [23, 24] or the newly developed matrix for evaluation of sex/gender consideration in epidemiologic studies [73], might be used.

Conclusion

The developed comprehensive checklist goes beyond a binary consideration of sex/gender, includes complex dimensions of sex/gender, integrates a comprehensive consideration of gender-related power relations and thus encourages a sex/gender-transformative research approach.

Table 2 Glossary of the most important terms
Full size table