05-20-2014 10:21 AM
I am not sure how you can get QI (or BMI as it is more commonly known) from a contingency table. Since it is a calculation (mass/(height*height)), a datastep to calculate it for each individual can be done, or PROC SUMMARY or MEANS could give group averages for mass and height, and from that a datastep could calculate a value.
05-20-2014 12:13 PM
What are the classes defining your contingency table? If those are weight (kg) and size (m) then take the center of each cell to calculate the QI.
Use the cell frequencies to get population statistics.