Diffusion of the D.A.R.E and syringe exchange programs.

We examined the diffusion of the D.A.R.E program to reduce use of illicit drugs among school-aged children and youths and the diffusion of syringe exchange programs to reduce HIV transmission among injection drug users. The D.A.R.E program was diffused widely in the United States despite a lack of evidence for its effectiveness; there has been limited diffusion of syringe exchange in the United States, despite extensive scientific evidence for its effectiveness. Multiple possible associations between diffusion and evidence of effectiveness exist, from widespread diffusion without evidence of effectiveness to limited diffusion with strong evidence of effectiveness. The decision theory concepts of framing and loss aversion may be useful for further research on the diffusion of public health innovations.