Temporal Stability of the MMPI-2 in a Substance Abuse Sample

Abstract

Determined test-retest stability of the standard validity and clinical scales and 12 supplemental scales from the MMPI-2. Also examined the stability of high-point, two-point, and three-point codes. Subjects were 100 male substance abusers with age and education means of 45.56 years (SD = 10.59) and 12.53 years (SD = 1.43). Subjects were divided into two subgroups: Group I (n = 51) had a retest interval of 5.27 months, while Group II (n = 49) had an interval of 13.46 months. For both Groups, all reliability coefficients were significant. However, Group I single, two-, and three-point code agreements across administrations were 31.4%, 19.6%, and 13.7%, respectively. Group II concordance rates for one-, two- and three-point codes were 34.7%, 12.2%, and 6.1%. Because Inventory results may show meaningful change on retest, clinicians should be cautious when making predictions about an individual patient from a single administration.