For much of the twentieth century, clinical research treated the adult male body as the default and assumed the findings would transfer. They often did not — differences in drug metabolism, symptom presentation and disease progression were missed for decades. The correction is not complicated: measure sex and gender properly, report them separately, and analyse whether they matter. The SAGER guidelines (Sex and Gender Equity in Research) are the standard that makes this concrete.
SAGER was developed by the Gender Policy Committee of the European Association of Science Editors (EASE) and published in 2016. It is listed on the EQUATOR Network. Like other reporting guidelines, it governs what you report, not how you design the study.
Two different variables
| Sex | Gender | |
|---|---|---|
| Refers to | Biological attributes: chromosomes, hormones, anatomy, physiology | Socially constructed roles, identities, expressions and behaviours |
| Typically reported as | Female, male, intersex | Woman, man, non-binary, other identities |
| Relevant to | Pharmacokinetics, disease risk, physiology | Access to care, health behaviours, exposure, adherence |
Both can affect a health outcome, sometimes in opposite directions — which is why collapsing them into one column labelled "gender: M/F" loses information.
Record where each value came from. Sex copied from a hospital record, sex established by a laboratory test and gender reported by the participant are three different data sources. If your records hold a single field, name it as the record does. Then say in the methods that sex and gender could not be separated.
What SAGER asks of authors
- Use the terms correctly and consistently throughout the paper.
- Report how they were determined — self-reported, from records, or measured — in the methods.
- Report data disaggregated by sex and, where relevant, gender, including in tables and supplementary material.
- Discuss the implications in the discussion, or state plainly that a sex/gender analysis was not possible and why.
- Justify a single-sex study rather than leaving the restriction unexplained — and say so in the title and abstract, which is what SAGER specifically requires.
SAGER section by section
| Section | What SAGER asks |
|---|---|
| Title and abstract | If only one sex was studied, or the results apply to only one sex or gender, say so |
| Introduction | Where relevant, state whether sex or gender differences might be expected |
| Methods | Report how sex and gender were taken into account in the design, whether males and females were adequately represented, and why either was excluded |
| Results | Present data by sex and gender where appropriate, and report sex- and gender-based analyses whether or not they found a difference |
| Discussion | Discuss the implications for the results; if no analysis was done, give the reason and discuss what that means for interpretation |
The International Committee of Medical Journal Editors (ICMJE) Recommendations make a similar request. They ask authors to use the terms sex and gender correctly and to report the sex of participants, animals or cells where appropriate. They also ask authors to describe how sex and gender were determined, to justify a study done in only one sex, and they point authors to the SAGER guidelines. For animal work, the ARRIVE 2.0 guidelines ask you to report the sex of the animals used.
Writing about participants respectfully
Describe people as people: "participants with diabetes", not "diabetics". Where gender identity is relevant, collect it with an inclusive question rather than a forced binary, and report the categories you actually used. If your sample contained too few participants in a category for separate analysis, say so — that is a limitation, not something to quietly merge away.
Collect gender identity only where it is relevant to your question and covered by your ethics approval. Report the exact wording of the question, as you would for any survey item. Our guide to reporting a questionnaire study covers the rest.
Analysing sex differences without overclaiming
A table split by sex is description. Claiming that an effect differs between females and males is an inference, and it needs a test of that difference, usually a sex-by-treatment interaction term in the model. Writing "significant in women but not in men" does not show a difference between them. The difference between a significant and a non-significant result is not necessarily significant itself.
Say whether the sex analysis was planned before the data were seen. A pre-specified analysis carries more weight than one chosen afterwards. Report its estimate with a confidence interval, as set out in our guide to p-values and confidence intervals.
The example below is invented to illustrate the structure; its numbers are not real data.
"Sex was taken from the hospital registration record (female/male); gender identity was not collected. Of 212 participants, 118 were female and 94 male. The sex-by-treatment interaction was pre-specified. It was not statistically significant (p = 0.41), but the study was not powered to detect it, so a difference between sexes cannot be ruled out. Sex-specific estimates with 95% confidence intervals are given in Supplementary Table 2."
Common errors and their fixes
- "Gender" used as the label for a record-based sex field — relabel the variable as sex, or state its source.
- Small categories merged or dropped without comment — report their numbers and state how they were handled.
- A sex difference claimed from separate subgroup p-values — test the interaction and report the estimate with its confidence interval.
Why journals are adopting it
SAGER sits alongside the other reporting standards you already meet — CONSORT, PRISMA and STROBE — and for the same reason: incomplete reporting makes research harder to use and to synthesise. Studies that disaggregate their data are more reusable, more citable in evidence syntheses, and more likely to be applicable to the patients who will eventually be treated on their basis.
Applying SAGER usually takes one extra column in a table and one honest paragraph in the discussion. That is a small price for research that describes the whole population it claims to be about.
Updated 5 September 2026: We added the SAGER instruction that single-sex studies should also state this in the title and abstract.
Updated 17 September 2026: We expanded this guide with a SAGER section-by-section table, the ICMJE and ARRIVE requirements, a worked example and common errors.