The numbing scale: Psychometric properties, a preliminary report

Abstract

This study explored the psychometric properties of a new self-report instrument, The Glover Numbing Scale©. The scale measures a variety of behaviors reported by individuals experiencing an inability to access feelings other than hostility and rage. The scale was administered to inpatient Vietnam combat veterans with post-traumatic stress disorder (PTSD, n = 323), PTSD diagnosed Veterans Affairs (VA) outpatient and veterans' outreach center veterans (n = 208), two Vietnam veteran non-combat groups (n = 45), two psychiatric non-combat controls (anxiety disorder, n = 40; major depressive disorder, n = 31), and a non-psychiatric never-in-Vietnam veteran control group (n = 48). Reliability information suggested that the scale was internally consistent with good test-retest correlations. Convergent and discriminant validations were assessed based on the pattern of the scale's correlations with relevant Minnesota Multiphasic Personality Inventory (MMPI) scales. The contrasting pattern of correlations provided by a subgroup of veterans who reported always feeling dead or shut down was highlighted. Principal component analysis resulted in a five-factor solution that provided evidence for the scale's factorial validity. Numbing Scale scores discriminated levels of psychopathology within the veteran population. PTSD outreach center veterans' sum scores and item scores on the Numbing Scale were more similar to responses of anxiety disorder patients than to major depressive disorder patients. Overall, the findings strongly support the clinical application of the Numbing Scale. Anxiety 1:70–79 (1994). © 1994 Wiley-Liss, Inc.