Validation of the spanish version of the discrimination and stigma scale (DISC 12)

The "Discrimination and Stigma Scale" (DISC) was the first instrument specifically designed to evaluate reported experiences of discrimination by people with mental disorders. This study aims to validate DISC-12 version in Spanish population with Schizophrenia and, as specific objectives, to do the external validation with the Self-Stigma Questionnaire (SSQ) scale and Link PDD scale and to validate their internal consistency, temporal and inter-rater reliability.

86 individuals with schizophrenia were interviewed at two time points (between one to two weeks) by two raters. Additionally to assess their sociodemographic and clinical characteristics, following scales were administered: DISC 12, SSQ, PDD, Social Functioning Scale (SFS) and Global Assessment of Function (GAF).

Internal consistency as a whole results a Cronbach a between 0.741 and 0.850. Subscales "Unfair treatmen" and "Positive treatment" have a Cronbach a higher than 0.79, but the both subscales "Stopping Self" and "Overcoming stigma" do not have in themselves an adequate consistency. Test-retest reliability shows that four subscales have values higher than 0.67. Inter-rater reliability assessment result that 21 items score values above 0.8, 10 between 0.6-0.8 and one lower than 0.6. DISC-12 was significantly related with the second factor of the PDD (self-stigma) and SSQ.

The Spanish version of the DISC 12 scale is valid, has good internal consistency, is reliable both in terms of test-retest and inter-rater reliability and has good convergent validity with the SSQ and PDD, and the "Unfair treatment" and "Positive Treatment" subscales were the most robust of the four subscales.