Diversity in research design

Cardiovascular diseases are often diseases of inequality, and many groups are currently under-served by cardiovascular research. As the biggest independent funder of cardiovascular research in the UK - investing around £100 million in research into conditions affecting the heart and blood vessels each year - BHF as a responsible research funder has a duty to help ensure that the research we fund is representative of, and could lead to future advances for, the people who need it. 

Our expectations

While we recognise that there is no perfect way of taking diversity into account when designing a research project, and that this may be more straightforward/easier for some types of research than others, BHF has the following expectations:

• Where appropriate, researchers we support should consider relevant demographic factors, such as age, sex, gender or ethnicity, in their research design and methodology. For example – when developing the research question, planning the target distribution/allocation of participants/animals/samples, research methods, or how data is collected and analysed. Please note that age, sex, gender and ethnicity is not an exhaustive list of characteristics that may be relevant.
• Where possible, research involving human participants/cells/data has a target sex and/or gender distribution reflective of the population that is affected by the condition being studied or that needs the healthcare intervention.
• Research involving animals or animal cells/data should not be single sex, unless there is a strong justification for doing so.
• Sex and/or gender-disaggregated analyses should be included where appropriate.
• BHF is prepared to consider funding costs associated with achieving a representative study design/population, where costs have been sufficiently justified.
  ​

Information for grant applicants

Applicants to BHF funding schemes involving a specific research project must provide information on: 

• whether and how factors such as age, sex, gender or ethnicity have been considered as part of the design of the research project
• the proposed sex and/or gender balance of the study population.

Information provided will form part of the assessment of research design and methods by our committee members and independent expert reviewers.

For research involving human participants, you may find it useful to refer to:

• University of Leicester Inclusivity Checklist for Clinical Research – a practical checklist of strategies to promote diversity and inclusion in clinical research, from setting the research question through to dissemination of results 
• Trial Forge resources on improving clinical trial diversity - including how to consider sex and gender in trials, guidance to support recruitment and retention of individuals from ethnic minority groups, and how to include older people/socioeconomically disadvantaged people/people with impaired capacity to consent in trials
• Burgess S, Zaman S, Towns C, Coylewright M, Cader FA. The under-representation of women in cardiovascular clinical trials: State-of-the-art review and ethical considerations. Am Heart J. 2025 – describes the use of participation to prevalence ratios to assess representation of women in clinical trials, and actions to increase participation of women in trials
• BHF guidance on patient and public involvement in research
• INCLUDE guidance on improving inclusion of under-served groups in clinical research
• Research inclusion toolkit hub on NIHR Learn - you will need to create an NIHR Learn login to access these resources

For research involving animals, you may find it useful to refer to:

• NC3Rs Experimental Design Assistant, Animal Characteristics guidance and webinar on Using both sexes in animal experiments
• Sex Inclusive Research Framework – a decision tree that gives a Green/Amber/Red rating for your research plan with regards to sex inclusion
• ARRIVE guidelines

Zaaijer S, Capes-Davis A. Ancestry matters: Building inclusivity into preclinical study design. Cell. 2021 May 13;184(10):2525-2531 includes recommendations for addressing diversity in cell-based models. 

Sex and gender

The MESSAGE (Medical Science Sex and Gender Equity) initiative has developed resources on how to consider and gender in research, including a sex and gender e-learning for researchers.

• Sex refers to the biological attributes which differentiate females and males. This can include variations of what are considered female-typical and male-typical characteristics (sometimes known as “variations in sex characteristics” or “intersex”).
• Gender refers to a person's identity of being a man, woman, non-binary or another gender. A person is subjected to a range of social and cultural forces based on their gender, which may influence their behaviours, their perception of themselves and how they are treated by others. Gender exists on a spectrum, can change over time, and intersects with other aspects of identity such as age, ethnicity and sexual orientation. How people experience and express gender can vary greatly within and across societies.
  ​

Information for grant holders

Progress reports

BHF Clinical Study Grant holders must submit regular progress reports, which include providing information on the demographics of the participants being recruited into the study and any actions taken to improve diversity of the participants. See reporting progress for details.

Final reports

BHF grant holders must submit a final report within 3 months of the end date of the grant. This report includes a section asking for information on whether and how factors such as age, sex, gender or ethnicity were considered as part of the design of the research project and the sex and/or gender balance of the study population. See reporting progress for details.