I wouldn't be enough of an authority to speak in those general terms outside of jurisdictions where I've worked. What I can say is that, in my opinion, correlation does not necessarily equal cause. With regard to safe consumption sites, or overdose prevention sites, we have one in the community of Prince George. As pointed out, there's been no overdose deaths there since it's been open, similar to most overdose prevention sites. However, we have had overdose deaths on the sidewalk out front where lots of people gather around.
I think it may be one piece of the puzzle, but I don't think it's the silver bullet to fixing everything.