Mobility for sex work and recent experiences of gender-based violence among female sex workers in Iringa, Tanzania: A longitudinal analysis.

Female sex workers are highly mobile, which may influence their risk of experiencing physical and sexual violence. However, there remains a paucity of research, particularly longitudinal, from Sub-Saharan Africa exploring mobility and gender-based violence among female sex workers. To address this gap, this study examined the longitudinal relationship between work-related mobility and recent experience of physical or sexual gender-based violence from a client or partner among female sex workers in Iringa, Tanzania. A secondary data analysis was conducted using baseline and 18-month follow-up data from Project Shikamana, a community empowerment-based combination HIV prevention intervention. Responses from 387 female sex workers aged 18 years and older participating in both baseline and follow-up were analyzed. Unadjusted and adjusted Poisson regression models with robust variance estimations, accounting for clustering of female sex workers' responses over time, were fit. Final models adjusted for socio-demographic characteristics and aspects of participants' living situations and work environments. Recent physical or sexual violence from a client or partner was common (baseline: 40%; follow-up: 29%). Twenty-six percent of female sex workers at baseline, and 11% at follow-up, had recently traveled outside of Iringa for sex work. In the final adjusted longitudinal model, female sex workers recently mobile for sex work had a 25% increased risk of any recent experience of physical or sexual gender-based violence when compared with their non-mobile counterparts (adjusted incidence rate ratio: 1.25; 95% CI: 1.03-1.53; p<0.05). Interventions must identify ways-such as mobile support services, linkages and referrals to health and other social services while traveling, or the use of mobile or digital technology-to address mobile female sex workers' unique needs while traveling. Future quantitative and qualitative research is needed to understand the context of female sex workers' mobility and how and why mobility influences risk environments and experiences of gender-based violence.