Measurement invariance and latent profiles of perfectionism in clients and nonclients.

The current study evaluated measurement invariance of the short Almost Perfect Scale-Revised (SAPS; Rice, Richardson, & Tueller, 2014) between large samples of 1,802 university counseling center clients and 1,040 university students. The clinical sample also completed the Counseling Center Assessment of Psychological Symptoms-62 (CCAPS-62; Locke et al., 2011), permitting tests to evaluate support for latent classes of adaptive, maladaptive, and nonperfectionists observed in other studies. Of particular interest was whether an "adaptive" group of perfectionists can be identified within a psychologically distressed sample of counseling center clients. Measurement invariance tests supported the 2-factor SAPS structure (Standards and Discrepancy) although scalar (intercept) noninvariance was observed. Within- and between-sample replication (similarity) analyses supported a 4-class model of perfectionists and nonperfectionists. Classes were distinguished by differing elevations of the 2 perfectionism factors that showed divergent patterns of psychological problems in the clinical sample. In the 4 classes that emerged in both samples, 1 class was consistent with a higher distress, maladaptive perfectionist group, whereas another class represented a less distressed adaptive perfectionist group. Two nonperfectionistic classes were consistent with groups of clients for whom perfectionistic strivings were not rated as important. As might be expected, there was a substantial difference in the frequencies of membership in the classes within- and between-samples, with proportionally fewer adaptive and more maladaptive perfectionists in the clinical sample than in this and other nonclinical university samples. Results have implications for the use of the SAPS as a screening and treatment planning instrument for use in university counseling centers. (PsycINFO Database Record (c) 2019 APA, all rights reserved).