Friendly Atheist today has a great post on a Christianity Today Article ( by the Fung brothers) that twists the STEP study for their purpose. Intercessory prayer does not work, but read his article to see the cool rationalization attempted by these Christians.
Many studies have been done of prayer and depending on who does them and methodology, occasionally one will show a slight effect in favor of god-power. Of course analysis always show a design fault or bias of the study, but come on ! It is GOD we are studying. In medicine, when we study difference between drugs, we look for small improvements in outcomes so we can switch from one drug to one which is a little better. But here, it is an ALL-POWERFUL compassionate god vs. no god which we are comparing. The God effect should NOT BE SUBTLE ! Seriously folks, this is not like comparing two drugs.