Prayers and Pie charts

There was this survey that I heard about a few days ago, it was conducted to find out if praying helped patients who were undergoing major surgery. Apparently, according to the survey, it does not.
Why would someone conduct such a survey?? Can you measure something like this and capture it in Excel?? I find that silly. I’ll tell you why.

I am not a religious person. I do not believe in rites and rituals. But I pray, everyday. I do not chant any mantra or recite any traditional prayers though. I talk to God and tell him/her to watch over my loved ones especially those who are going through tough times. After that I feel good. I feel I have appealed to some power that I cannot comprehend but I know exists. It calms me down when things are not going quite the way I wish they would. The reason I talk to my God is because I have done everything in my power to make things right and if that does not work I might as well ask for some help from someone, who I believe may be able to help. I believe that is the reason most people pray. So when one is undergoing a life altering surgery what else is there to do other than ask for divine help? How can a bunch of analysts with pie charts tell the world that all the prayers in the world will not help you get through your ordeal? When that maybe the only redeeming factor.