Measurements of suicidal ideation in ecological momentary assessment based on smartphone: a systematic review

Understanding suicidal ideation (SI) in real time has become a growing focus in suicide research, leading to an increasing use of ecological momentary assessment (EMA). However, substantial heterogeneity in how SI is measured, together with limited psychometric evidence for EMA-based SI measures, poses methodological challenges for consistency, interpretation, and validity.

This systematic review followed PRISMA guidelines and searched 9 databases (5 international and 4 Chinese) through August 2025. Peer-reviewed studies employing smartphone-based EMA to assess SI were included. Data were extracted on measurement characteristics, item content, and reported psychometric evidence.

A total of 89 studies met the inclusion criteria. SI items originated from three main sources: adapted from standardized scales (51.7%, n = 46), custom-developed items (21.3%, n = 19), and hybrid approaches (27.0%, n = 24). Conceptualizations of SI varied substantially, with over half of the studies (57.3%) distinguishing multiple dimensions of SI. More than one-third of studies (n = 29) relied on single-item assessments. Fifteen studies reported at least one form of psychometric evidence.

This review provides a comprehensive synthesis of current practices in measuring SI using smartphone-based EMA. The findings highlight substantial methodological variability and limited psychometric reporting, underscoring the need for clearer construct definitions, greater transparency in measurement design, and strengthened validation efforts to improve comparability and interpretability in future EMA research.

CRD420251112259.