Development and psychometric validation of new questionnaires assessing experienced discrimination and internalised...

To develop and validate two new standardised measures assessing, respectively, experienced discrimination (Covid-19 Experienced DISCrimination scale, CEDISC) and internalised stigma (COvid-19 INternalised Stigma scale, COINS) in people who had been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or had developed coronavirus disease 2019 (Covid-19) disease.

Both the CEDISC and the COINS were developed in Italian and tested for ease of use, comprehension, acceptability, the relevance of items and response options within a focus group session. Online cross-sectional validation survey was conducted among adults infected with SARS-CoV-2 or who developed Covid-19 disease, members of a closed Facebook discussion group in Italy. Exploratory factor analysis (EFA) with Promax oblique rotation; the Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy and the Bartlett's test of sphericity were used to assess the suitability of the sample for factor analysis. Reliability was assessed as internal consistency using Cronbach's alpha and as test-retest reliability using weighted kappa and intraclass correlation coefficient (ICC). Precision was examined by Kendall's tau-b coefficient.

Overall, 579 participants completed the CEDISC, 519 also completed the COINS, 155 completed the retest for both scales after two weeks. The 12 items of the CEDISC converged over a 2-factor solution ('social life' and 'close relations') accounting for 49.2% of the variance (KMO = 0.894; Bartlett's test p < 0.001); the 13 items of the COINS converged over a 3-factor solution ('self-perception', 'close relations' and 'social life') accounting for 67.7% (KMO = 0.827; Bartlett's test p < 0.001). Cronbach's α was 0.848 for the CEDISC, and 0.837 for the COINS. The CEDISC showed three items (25%) with kappa between 0.61 and 0.80 and seven (58.4%) between 0.41 and 0.60, with only two items scoring 0.21 and 0.40; the COINS had ten items (76.9%) with kappa ranging from 0.41 to 0.60, and three items below 0.31. ICC was 0.906 (95% CI, 0.871-0.932) for the, CEDISC and 0.860 (95% CI, 0.808-0.898) for the COINS. Kendall's tau-b ranged from 0.360 to 0.556 (p < 0.001) for the CEDISC and from 0.290 to 0.606 (p < 0.001) for the COINS.

Both the CEDISC and the COINS are two valid and reliable scales to be used in studies examining the role of stigma and discrimination of people infected with SARS-CoV-2 and Covid-19 patients, and in research evaluating interventions designed to mitigate stigma in this population.