In this context, they specify 4 levels of risk causation in sex work: societal (superstructural), community (structural), institutional (infrastructure/environment), and individual.
Overs  has categorized 3 levels of intervention strategies for FSWs: individual/cognitive, participation and empowerment, and structural/environmental.
In this article, we describe the results of a mapping study and a sociobehavioral survey of FSWs in Karnataka, with a particular emphasis on comparing the sex work patterns and environment associated with the The study was conducted in the southern Indian state of Karnataka, which has a population of ∼55 million.
Various program strategies have been successful for STI/HIV infection prevention among FSWs.
Some of these strategies were designed as individual/cognitive interventions through peer outreach and education [4, 5].
Partner organizations for the implementation of the survey included the Population Research Centre (Dharwad, Karnataka), which was the lead agency for planning and implementation, 3 nongovernmental organizations (NGOs) that are implementing prevention programs for FSWs (Belgaum Integrated Rural Development Society [Gokak, Karnataka, India], Samraksha [Bangalore, Karnataka, India], and the Society for People’s Action in Development [Bangalore, Karnataka, India]), and the Federation of Sex Worker Collectives in Karnataka (Sahabhagini).
With these partner organizations, an advisory committee was formed to develop and agree on the design of the survey, the questionnaire structure and content, and the implementation strategy.
This formulation is perhaps less theoretical but still emphasizes the importance of designing programs that address factors at both the individual and the structural/environmental levels, to reduce the vulnerability of FSWs.