I have been reading posts during the COVID-19 lock-down. Many of my friends do not know what solid statistical evidence is. I promise to keep the technical terms to an absolute minimum and avoid equations like the plague (or COVID-19 in our case).
Let’s consider if Church of God members have a higher blood pressure than Baptist. Anecdotal evidence works like this. You go to a Church of God church. One Wednesday night, two people ask for prayer about their high blood pressure. You call Aunt Diane the next day and tell her about the prayer requests. Your aunt Diane, a Baptist, says that is odd because no one at her church mentions their high blood pressure. That is anecdotal evidence. It is only good enough to make you ask questions.
You get curious about your aunt’s comments. You ask your pastor if you can take blood pressures at the next meeting. Then you ask Aunt Diane’s pastor if you can take blood pressure at his church the following Sunday. You compare the blood pressure of the two groups. Your church has a higher average blood pressure than the Baptist church. That is an observational study, and it is good enough for you to make a guess. It is not proof, but it is good enough to ask folks to inconvenience themselves for your proof.
Why is the observational study not proof? Let’s say your Church of God was founded by Brother Jones. A true man of God with a vision and a lot of children although he died at 40 from a massive stroke. Brother Jones had a strong genetic predisposition for high blood pressure. Half of your church are direct descendants of Brother Jones. The Baptist church was founded by Brother Smith. He was equally a good man with a lot of children. His blood pressure was good until the day he died at 101. Half the Baptist church were his direct descendants.
Here is why an observational study is not good proof. Your church hears about your study. Half of the members of the church has high blood pressure and on medication with dietary restrictions. They want the blood pressure of a Baptist. They leave your church and go to the Baptist. They quit taking their medication. They start eating very salty food again. Your church cannot survive with only half its members and closes. The new Baptist start having strokes. AN OBSERVATIONAL STUDY IS NOT PROOF!
Good news! A controlled study is considered proof. This is how you would do a controlled study. You go to both pastors and get their church rolls. You combine the church rolls. You take everyone’s blood pressure and explain that folks should continue life as normal except for any church change you ask them to make. You randomly group the members into two groups. One randomly selected group starts going to the Baptist church and the other randomly selected group starts going to the Church of God. Six months later you take blood pressures again and compare.
Let me point out why this is important. What do you want your doctor to do if you have high blood pressure? Do you want him to tell you to leave the Church of God and go to a Baptist church because his Aunt Diane has never heard someone request prayer for high blood pressure at her church? Or, do you want him to tell you to eat better and take this pill?
Pray for our medical community during these trying times and don’t spread conspiracy theories. Misinformation during a pandemic fills body bags. Pray for the brave souls agreeing to be subjects in the clinical trials. They are taking risks for the public good. God bless them. God bless America