Measuring infectious disease stigma in the German population: Psychometric properties of stigma scales related to COVID-19, Long Covid and non-vaccination in a representative population sample

Background The COVID-19 pandemic was widely accompanied by stigma towards certain groups of people, which can diminish efforts of disease control and exacerbate negative impacts of the disease itself. Research on COVID-19-related stigma in the German population is scarce and, internationally, is lacking validated and standardized measurement instruments. To address this issue, this study tested the psychometric properties of a set of scales to measure COVID-19-related stigma in a representative sample of the German population. Methods Overall, 1960 people (M(SD)age = 49.8(17.3) years, 55.8% female) participated in a nationally representative cross-sectional survey in Germany. Six scales were tested, assessing public attitudes towards people who have had COVID-19 (COVID-PSS), those who had the disease multiple times (MI-PSS), people with Long Covid (LC-PSS) and people who chose not to get vaccinated (nonVac-PSS). We further assessed internalized stigma of individuals, who have had COVID-19 at least once (COINS) and those who chose not to get vaccinated (nonVac-IS). All scales were tested for their intended factorial structure through confirmatory factor analysis, convergent and discriminant validity and reliability. Results All scales, excepting the scale for internalized stigma of unvaccinated individuals, showed good to excellent fit indices and factor loadings, supporting their intended factorial structure. Convergent and discriminant validity were established for the public stigma scales. The COINS did not converge with a measure of quality of life, but with depressive symptoms, whereas the nonVac-IS did not show convergence with presumed related constructs. Reliability coefficients showed good internal consistency among the items. Conclusion Five out of the six scales proved to be valid tools to measure stigmatizing attitudes related to COVID-19, Long Covid and non-vaccination in a German sample. The scales hold promises for monitoring stigma during infectious disease outbreaks and informing the development of public health interventions to counteract health-related stigma.