Qlikview has some regression functions (check out the ones beggining "LINEST..", but be aware that they are limited to linear only, not multiple.
The function for returning the coefficient for 2 fields is: linest_m(y,X)
So you could use this like
=linest(COPD_Rates,Smoking_Rates) to look at the relationship between smoking rates and copd (emphysema rates)
Most people's data isn't this straight forward and you can use it in conjunction with aggr to compare grouped results, eg
Other useful functions that work in the same way:
Linest_b : intercept
Linest_r2: correlation squared
I personally prefer to do the regression in another program (eg R or SPSS) and import the results into QlikView if it's anything more complex than the above!
Hope this helps,