I'm learning R in a Bachelor course for the Biology bachelor and had to use the riskratio() function (from the epitools package) for the first time. I'm looking at an example script the teacher posted and I don't know how I'm supposed to know when to not use the rev = "neither" argument. I know what rev does, but I'm not sure how to spot when to use it.
The dataset consisted of the gender and whether or not the person survived during the titanic accident and the goal of the assignment was to calculate the relative risk of death for men relative to the women. We had to make a table with the frequencies of dieing and surviving for both men and women and than calculate the relative risk. The rows on the table were defined by gender and the columns by survival. Men-Died was in the top left and Women-Survived in the bottom right.
My question is why we had to use rev = "both" in this case and how do I decide whether to use it or not the next time?
Thanks for reading this and have a great day :)