I'm analyzing an experiment results. The experiment (unfortunately) was very bad designed .. anyhow this is what I have ....
In this experiment two group of patients: healthy control and with X disease. The sick people came for three visits: during the first visit they took no medication at all. During the second meeting they took Type 1 medication, and during the third meeting they took Type 2 medication. During each meeting blood samples for testing was taken from the sick people. The control group of healthy subjects arrived for only one visit during which they also had blood tests. All blood test measured the amount of Y protein. To summarize, I have four kinds of Y protein samples: from healthy people; from sick people that did not receive medication; from sick people on Type 1 medication; from sick people on Type 2 medication. I have three hypotheses that I would like to test -
- That there is a clear statistical difference between the sick and healthy people (for the duration of all the visits), that is, from an aspect of protein amounts, both types of medication did not raise the level of protein to that of the healthy people.
- That the medication did improve the level of protein in sick people, and the amount of protein is indeed statistically different between sick people on medication, and in sick people not on medication.
- That there is no statistical difference in the amount of protein that measured between the two types of medication.
my question is: how should I design my t-tests for testing those three hypothesis ( contrast ?) ? while avoiding overlap tests ( orthogonal ?) puzzled... any help would be appreciated!