What methods are available if there are no responses in a 2x2 table. For example, when analyzing proportion differences between treatments by Gender, neither Male nor Female have any responses (e.g. the counts are zero for both), so FREQ will not estimate the CIs for the difference in proportion. To get around this, I placed a very small non-zero value in the counts table, say 0.000000001 for the zero response counts and then processed it with FREQ using EXACT and RISKDIFF. Should some other method be used, and if so, what is it?
... View more