Table 1.

Summary of ‘sex’ and ‘gender’ definitions.

	N	Definition provided?	Where a definition was provided, was the term defined/used correctly?	Proxy measure provided for sex and/or gender?
Studies using ‘sex’ term	57	33.3% Yes (N = 19) 66.7% No (N = 38)	100% Yes (N = 19)	3.5% Yes (N = 2); participants were assigned to the female/girl or male/boy group based on parent-report of biological sex designated at birth 96.5% No (N = 55)
Studies using ‘gender’ term	12	No (12, 100%)	N/A – no definition provided	None for all studies