Development of the Experiences of Sex Work Stigma Scale Using Item Response Theory: Implications for Research on the Social Determinants of HIV.

While HIV stigma has received significant attention, limited work has been conducted on the measurement of intersecting stigmas. We developed the Experiences of Sex Work Stigma (ESWS) scale in the Dominican Republic (DR) and Tanzania. We conducted in-depth interviews with 20 female sex workers (FSW) per country to identify scale domains followed by cognitive debriefing interviews to assess content validity. Items were administered in a survey to FSW in DR (n = 211) and Tanzania (n = 205). Factor analysis established four sex work stigma domains including: shame (internalized), dignity (resisted), silence (anticipated) and treatment (enacted). Reliability across domains ranged from 0.81 to 0.93. Using item response theory (IRT) we created context-specific domain scores accounting for differential item functioning between countries. ESWS domains were associated with internalized HIV stigma, depression, anxiety, sexual partner violence and social cohesion across contexts. The ESWS is the first reliable and valid scale to assess multiple domains of sex work stigma and can be used to examine the effects of this form of intersectional stigma on HIV-related outcomes across settings.