I have two distinct groups made of a different numbers of subjects (111 Millions and 126 Millions). My goal is to evaluate how many subjects in the two groups encounter 10 different diseases. For this purpose, I build a table (reporting here only 4 out of 10 diseases) as follows:
|Disease||Group A||Group B|
|A||23 M||19 M|
|B||45 M||18 M|
|C||19 M||18 M|
|D||21 M||20 M|
In this case there are no means involved: I'm simply counting the number of occurrences (frequency) within each group and for each disease. Is there a way to check whether the the difference is statistically significant for each disease between the two groups? I would proceed with a Chi-squared test isolating each disease, building a contingency table as follows and then run the test.
|Disease A||Group A||Group B||Sum|
|Infected||23 M||19 M||42 M|
|Not-Infected||88 M||107 M||195 M|
|Sum||111 M||126 M|
Is, in this case the Chi-squared test, the most appropriate test?