Psychometric Analysis of the Barber Suggestibility Scale in a Clinical Population

Abstract

The aim of the study was to administer the Barber suggestibility scale to a clinical population in Spain and to examine its psychometric properties therein. The reliability and factor structure of the adapted scale was compared with that of the original (American) scale and with data from two other versions (British and Puerto Rican samples). Sex differences in suggestibility were also analyzed. The Barber suggestibility scale was administered (without preliminaries) to a sample of 283 patients (130 women, 153 men) with a range of diagnoses: anxiety disorder (33.9%), substance-related and addictive disorder (25.8%), mood disorder (12.7%), somatic symptom disorder (4.6%), trauma- and stress-related disorder (3.5%), and other disorders (19.5%). Results indicated a higher degree of suggestibility among women, with the effect size being low (d = 0.26) for the objective subscale and moderate (d = 0.55) for the subjective subscale. Therefore, normative scores were reported by sex for both subscales. As a whole, the present clinical sample showed higher suggestibility than has been reported previously for nonclinical populations (p < 0.001; d = 1.56). Reliability indices (Cronbach’s alpha and split-half/Spearman-Brown) for the present adaptation in a clinical population indicated acceptable internal consistency (range 0.70–0.82). Applied to a clinical sample the Barber suggestibility scale showed a three-factor structure for the objective subscale and a more complex structure for the subjective subscale. These results suggest that the Barber suggestibility scale is a suitable instrument for assessing the degree of suggestibility in persons with a clinical disorder.