Another study from the same page:

"http://onlinelibrary.wiley.com/doi/10.1111/j.1523-536X.1987.tb01444.x/abstract"

"These findings are consistent with studies of other settings in which the place of birth was shown to have an impact on childbirth experience, thus demonstrating that birth centers can oversee childbirth as safely and with less intervention than do hospitals"

The important thing, as this study pointed out, is that this is "consistent with other studies."

Again, don't get hung up on the fact that in my quick scan of the search results, I misrepresented one study, that is an error quickly fixed, as I've already retracted that claim. The POINT is the broad research is there in the link I provided for anyone willing to look through it.