Measurement Invariance of the Suicide Cognitions Scale-Revised (SCS-R)

The Suicide Cognitions Scale-Revised (SCS-R) is a unidimensional measure of suicidal cognitions theorized to assess the suicide belief system. Several solutions have been proposed for the Suicide Cognitions Scale and SCS-R (e.g., bifactor model with two specific factors, bifactor model with two specific factors, three correlated factors model). Research indicates the endorsement of thoughts of suicide and suicide-related cognitions varies across demographics. Thus, the current investigation tested the measurement invariance (MI) of the SCS-R across gender, race, and sexual orientation within these proposed solutions and a unidimensional model. A national sample of N = 10,625 adults completed an online survey that included the SCS-R and self-report measures of demographics. Results indicated that the bifactor model with three specific factors, the bifactor model with two specific factors, and the three correlated factors models achieved scalar invariance across gender, race, and sexual orientation; a unidimensional model was not scalar invariant by gender. Tests of latent mean differences revealed significant differences in the general factor (i.e., suicidal belief system) and the specific unlovability, unbearability, and unsolvability factors between a few demographic groups. Implications for theory, measurement, and modeling are discussed. Public Significance Statement The Suicide Cognitions Scale-Revised is an instrument that measures the suicidal belief system, evinces measurement invariance, and is strongly related to and is predictive of other thoughts and behaviors on the suicide spectrum. Instruments that are measurement invariance for diverse groups of people ensure confident score comparisons between groups and equitable clinical decision making across mental health care systems.