Systematic review of instruments for measuring sex and gender attributes: Assessment of measurement properties and utility in research on clinical and functional outcomes

Objectives To identify and synthesize instruments used to assess sex and gender attributes in relation to clinical and functional outcomes in adults. Methods We searched four databases from inception to November 20, 2023, to identify English-language studies on clinical and functional outcomes that used instruments of sex and gender attributes. On July 20, 2025, we searched MEDLINE for studies on the measurement properties of the instruments previously identified. We used Holmbeck and colleagues’ evidence-based criteria and rated quality based on measurement properties including frequency of use by independent researchers, validity and reliability in relevant populations, and sufficiency of information for replication and appraisal. Results Of the 12,964 unique records identified through our primary searches, 46 studies met our inclusion criteria. Eighteen of the studies had male-only samples, five had female-only samples, and the remaining included samples featuring both sexes. One study included transgender and nonbinary people. These studies utilized a total of 34 instruments, of which eight assessed sex and 26 assessed gender attributes. We assigned high quality scores to three instruments measuring sex and three instruments measuring gender attributes. We rated the remaining instruments on sex attributes and 14 instruments on gender attributes as moderate in quality, and the rest as low quality. Conclusion The measurement properties of instruments measuring attributes of sex and gender in relevant populations varied. Construct validity was the most reported property, and test-retest reliability was the least reported on. Validation of the scores in non-binary samples is limited. Further validation and application of high-quality instruments is timely for advancing equitable practices and policies.