Notes on the use of OpenEpi for lesson 15:
OpenEpi will perform matched analysis for pair matched data if you input the data in the form of the McNemar’s table. You must select Matched Case-Control from the counts folder. Please be very careful about the orientation of this table. In ActivEpi, Control is across the top and Case is on the left. This is just the opposite of OpenEpi where Case is across the top and Control is on the left. (I haven’t figured out how to change this.) Please input the data from page 485 of the companion text. You will need to make sure you enter the cells correctly in the table to get the appropriate results. Once you have entered the data you will notice that OpenEpi refers to the mOR as Pair-Matched Odds Ratio. It is simply a Mantel-Haenszel odds ratio calculated for 63 strata. (You would get the exact same results if you input 63 two by two tables.) You will also notice that OpenEpi refers to the Mantel-Haenszel chi-square as McNemar test. You should see the following results which are the same results that are shown on the bottom of page 485 in the companion text. Pair-matched OR = 9.667, 95%CI = (2.945, 31.73), McNemar: 21.13, p=0.000004307
For R to 1 matching or frequency matching, you will have to enter each of the strata just as you did for the typical stratified analysis in the previous lesson. You may wish to enter the 4 strata shown on page 493 in the companion text to reproduce the results shown there. Please note that the aOR is not provided in the OpenEpi output, however, you will see that it is identical to the mOR in this case.