Assessment of stigma in Spanish people with chronic pain using the 8-item Stigma Scale for Chronic Illnesses (SSCI-8)

Stigma is common in people with chronic pain. At present, however, the measurement of stigma in Spanish-speaking individuals remains a challenge due to a lack of validated measures in Spanish. The present study examines the psychometric properties of the Spanish version of the Stigma Scale for Chronic Illnesses 8-item version (SSCI-8) in people with chronic pain, focusing on dimensionality, factorial invariance, reliability (internal consistency and test-retest), and construct validity. Adults with chronic pain in Spain were recruited from patient associations and social networks to complete an online survey. The final sample comprised 530 individuals aged 18-70, predominantly women (> 90%). Half of the sample completed the SSCI-8 on a second occasion four weeks later. Data analyses supported a one-factor model with correlated errors as the most optimal solution for the SSCI-8 (CFI =.988; TLI =.983; WRMR =.938; RMSEA =.093; 95% CI [.076,.110]) and factorial invariance across different subgroups. SSCI-8 scores showed a normal distribution, good internal consistency, and adequate stability over time. Significant positive correlations were found, as expected, between stigma and depression, anxiety, pain intensity, pain interference, disability, and injustice experiences. Likewise, significant negative correlations were observed with psychological flexibility. The SSCI-8 accounted for incremental variance beyond injustice experiences in predicting the clinical outcomes. The Spanish version of the SSCI-8 appears psychometrically sound as a measure of stigma for use in people with chronic pain. PERSPECTIVE: The full invariance evidence across gender and pain type reported means that total score differences are due to real differences in perceived stigma, rather than observed differences in interpretations of item contents between men and women in pain or with different types of pain.