The use of structural equation modelling and behavioural theory to target priority interventions to increase condom use among the intimate partners of sex workers in French Guiana.

French Guiana is the French overseas territory that is most affected by HIV. Sex work seems to be an important driver of the epidemic. Although female sex workers are informed by local NGOs, they still have risky behaviours, including not using condoms with their intimate partner despite knowing HIV is highly prevalent. The objective of this study was to find intervention targets on this specific behaviour. For this, a structural equation model (SEM) was built using assumptions from behavioural theories. Behaviour theories attempt to connect research and practice. Within the health belief model framework, perceived threats, perceived benefits, and self-perceived efficacy were tested. Vulnerability was added because of the particular context of French Guiana. The results highlight that female sex workers' perceived self-efficacy was central in condom use with the intimate partner (with a significant correlation coefficient of 0.52 in the SEM). The perceived self-efficacy was strongly influenced by sociodemographic factors, particularly by nationality. Female sex workers from Brazil seemed to be more comfortable about asking their intimate partner to use condoms (OR: 7.81; CI: 1.87-32.63) than sex workers of other nationalities. These results emphasize that prevention interventions for female sex workers should emphasize their empowerment.