In this academic paper, the authors investigated how syringe service programs can prove their cost effectiveness by calculating how many HIV infections the program would need to prevent in order to be considered cost-saving. The study concluded that the syringe service program would only need to prevent three HIV infections in their community to be considered cost effective.
Des Jarlais, D. C., Feelemyer, J., McKnight, C., Knudtson, K., & Glick, S. N. (2021). Is your syringe services program cost-saving to society? A methodological case study. Harm Reduction Journal, 18(1).