The cost-effectiveness of the WINGS intervention: a program to prevent HIV and sexually transmitted diseases among high-risk urban women

Abstract

Background: We evaluated the cost-effectiveness of the WINGS project, an intervention to prevent HIV and other sexually transmitted diseases among urban women at high risk for sexual acquisition of HIV.

Methods: We used standard methods of cost-effectiveness analysis. We conducted a retrospective analysis of the intervention's cost and we used a simplified model of HIV transmission to estimate the number of HIV infections averted by the intervention. We calculated cost-effectiveness ratios for the complete intervention and for the condom use skills component of the intervention.

Results: Under base case assumptions, the intervention prevented an estimated 0.2195 new cases of HIV at a cost of $215,690 per case of HIV averted. When indirect costs of HIV were excluded from the analysis, the intervention's cost-effectiveness ratios were $357,690 per case of HIV averted and $31,851 per quality-adjusted life year (QALY) saved. Under base case assumptions, the condom use skills component of the intervention prevented an estimated 0.1756 HIV infections and was cost-saving. When indirect HIV costs were excluded, the cost-effectiveness ratios for the condom use skills component of the intervention were $97,404 per case of HIV averted and $8,674 per QALY saved.

Conclusions: The WINGS intervention, particularly the two sessions of the intervention which focussed on condom use skills, could be cost-effective in preventing HIV among women.

Figure 1

Simplified version of structural equation model used to evaluate the effectiveness of the WINGS intervention. The regression coefficient linking the Treatment or Control Group Status variable and the Odds of Condom Usage is (A*B) + (C*E*F) + (A*D*F), where A,B,C,D,E, and F were obtained from Greenberg et al., 2000 [10].