The DIFFER project was based on the hypothesis that combining vertical SRH interventions, such as services targeted to female sex workers (FSW), with horizontal health systems strengthening by integrating a broader range of SRH services within existing health facilities, is synergistic, feasible, and likely to be more effective and cost-effective than providing them separately.

In particular, the research activities built capacity to implement interventions for FSW, utilising the best practice experiences of partners in Mysore and Kolkata, India (Ashodaya and DMSC Sonagachi) where successful interventions for sex workers had been brought to scale. These was applied and adapted to 3 research sites in sub-Saharan Africa (SSA) in Kenya, Mozambique, and South Africa, focusing on integrated SRH care delivery to two populations of women: 1) female sex workers, and 2) women in the ‘general population’ who attend public health facilities, many of whom are also at high risk for poor SRH outcomes. These 2 populations have extensive overlap, with many of the ‘general population’ practicing some form of transactional sex, and many women who repeatedly enter and exit sex work, or are part-time sex workers.

DIFFER focussed on two channels for delivering improved SRH services; (1) through public facilities at district or primary level where women are already receiving some services, such as FP and HIV counselling and testing (HCT), and (2) through interventions designed with and for FSW in the communities where they work, through outreach and special mobile or satellite clinics.  The latter services are referred to as Targeted Interventions (TI). This bidirectional or ‘diagonal’ approach proposed builds on the strengths of both horizontal and vertical programming for maximum impact, as illustrated in the figure below.