Sex and gender in the US health surveillance system: a call to action.

Youth Risk Behavior Survey (YRBS) data have exposed significant sexual orientation disparities in health. Interest in examining the health of transgender youths, whose gender identities or expressions are not fully congruent with their assigned sex at birth, highlights limitations of the YRBS and the broader US health surveillance system. In 2009, we conducted the mixed-methods Massachusetts Gender Measures Project to develop and cognitively test measures for adolescent health surveillance surveys. A promising measure of transgender status emerged through this work. Further research is needed to produce accurate measures of assigned sex at birth and several dimensions of gender to further our understanding of determinants of gender disparities in health and enable strategic responses to address them.