"The rate of overdose observed at the Vancouver SIF is within the range of rates observed in an international review of SIF which estimated the rates of overdose typically to be between 0.01 and 3.6 per 1000 injections (Kimber et al., 2005). However, the rate observed in Vancouver is lower than rates observed recently in Munster, Germany (6.4 per 1000 injections) and Sydney, Australia (7.2 per 1000 injections) (Kimber et al., 2003). This may reflect differences in threshold for coding and intervention by staff, and differences in drug consumption patterns across cities, especially as it pertains to the use of opioids and other central nervous system depressants."

Source

Thomas Kerr, Mark W. Tyndall, Calvin Lai, Julio S.G. Montaner, Evan Wood, "Drug-related overdoses within a medically supervised safer injection facility," International Journal of Drug Policy 17 (2006) p.440.