NEEDLE EXCHANGE PROGRAMS - AN ECONOMIC-EVALUATION OF A LOCAL EXPERIENCE

Objective: To determine whether providing a needle exchange program to prevent HIV transmission among injection drug users would cost less t han the health care consequences of not having such a program. Design: Incidence outcome model to estimate the number of cases of HIV infect ion that this program would prevent over 5 years, assuming that the HI V incidence rate would be 2% with the program and 4% without it, and t hat an estimated 275 injection drug users would use the service over t his time. Setting: Hamilton, Ont. Outcome measures: Estimated number o f cases of HIV infection expected to be prevented with and without the program over 5 years; estimated lifetime health care costs of treatin g an AIDS patient. The indirect costs of AIDS to society (e.g., lost p roductivity and informal caregiving) were not included. Projected cost s were adjusted (discounted) to reflect their present value. In a sens itivity analysis, 3 parameters were varied: the estimate of the HIV tr ansmission rate if no needle exchange program were provided, the numbe r of injection drug users participating in the program, and the discou nt rate. Results: With very conservative estimates, it was predicted t hat the Hamilton needle exchange program will prevent 24 cases of HIV infection over 5 years, thereby providing cost savings of $1.3 million after the program costs are taken into account. This translates into a ratio of cost savings to costs of 4:1. The sensitivity analysis conf irmed that these findings are robust. Conclusion: Needle exchange prog rams are an efficient use of financial resources.