The use of ecological momentary assessment (EMA) in suicide-related research has become more common. To decrease participant burden, single-item indicators (SIIs) have become more widely used by researchers conducting EMA studies. The present study aims to provide preliminary psychometric information on several SIIs used to assess suicide-related thoughts and related risk/protective factors in EMA research. This study evaluated the psychometric properties of several SIIs used in EMA research across two studies. Study 1 was a cross-section study of N = 888 students (78.8% cisgender women, 67.1% White, 77.3% heterosexual); Study 2 was an EMA study of N = 52 students with recent suicidal ideation (69.8% cisgender women, 62.8% White, 41.9% heterosexual). All SIIs demonstrated acceptable convergent validity, discriminant validity, and short-term predictive validity. Additionally, within-person and between-person variability was observed for each SII across the EMA testing phase. Results provide preliminary psychometric support for the use of these SIIs. Establishing a set of SIIs for use in EMA research on suicide can aid in the interpretation of findings across studies. Future research is needed to further evaluate the use of SIIs in EMA studies.
