Creating a loop to replace value x if value y is among 20 variables

[Birgitte Tholin]

Hi,

Im quite new to Stata, but get by with using the manual and this forum. I´ll try to explain my problem as precise as possible and apologise in advance if I'm using the wrong terms.

I have a dataset of 4.000.000 on patients hospitalised with viral infections. One complication during hospitalisation is an arterial thromboembolism, and I'm trying to make the variable ATE_type with values 1-8 for the different types based on the discharge diagnosis code (diagnosis_1_1......diagnosis_20_1) which is in string format.

At first I used the following code:

gen ATE_type=.
replace ATE_type=1 if diagnosis_1_1=="I740"

Its simple, but to copy/retype the code 8 times for all 20 diagnosis variables is too inefficient. I've tried reading the manual and this forum, but don't understand how to make a loop that can replace the ATE_type value if a certain code e.g. "I740" is found in any of the 20 diagnosis code variables.

Can anyone help me?

Thanks in advance!

[Øyvind Snilsberg]

I believe this will get you almost what you want,

gen ATE_type=.
foreval i = 0/9 {
foreach v of var diagnosis* {
replace ATE_type = `i' if `v' == "I74`i'"
}
}

[Birgitte Tholin]

Thank you so much! That worked perfectly!