"Evaluation of the Vancouver facility has shown that its opening has been associated with reductions in public drug use and publicly discarded syringes and reductions in syringe sharing among local injecting drug users. Our study suggests that these benefits have not been offset by negative changes in community drug use."

Source

Kerr, Thomas, Jo-Anne Stoltz, Mark Tyndall, Kathy Li, Ruth Zhang, Julio Montaner, Evan Wood, "Impact of a medically supervised safer injection facility on community drug use patterns: a before and after study," British Medical Journal, Vol. 332, Jan. 28, 2006, p. 222.