Better than you do, apparently. Why is it, minnie, that the millions of dollars spent desperately trying to prove that shs causes harm hasn't been able to do it? And still you say ""I'm right, and I know I'm right because they wouldn't keep proving I was wrong if I wasn't right."
Unfortunately, it means "nothing". There is no "statistical" evidence either way. It doesn't mean there isn't a causal relationship, it just means the science of statistics are unable to prove one.