Because faith healing is a specific treatment, which does not consistently out-perform the control group.yes and a quarter of the control group got better with out a drug, how does that not support faith healing?
Now, perhaps you and I are using the term "fath healing" differently? To me, it refers to healing through religious intervention - an approach not found to consistently out-perform placebo approaches. If you're referring to the body's ability to heal itself (or at least to relieve symptoms), that's pretty much what accounts for much of the placebo effect. Mind you, we'd also need a second control group that receives absolutely no treatment, to establish that the placebo group improves at a significantly higher rate. If 23% of our no-treatment group improves, and 25% of our placebo group, that's probably not a statistically significant difference (unless we have a very large study population). If the no-treatment group sees a 10% rate of improvement, we have a high incidence of placebo effect, which implies faith-healing might achieve that same efficacy with people who believe in its effect. As would any other treatment they believed would work.