There are two types of variables: 1. Variables which can be saved in files. In Entry these are defined in the qes file, e.g. var1 Label for this variable #### After creating the data file (rec file) and entering data, the data are stored in a rec file

In Analysis variables can be created in two ways: a. Define var1 ###### var1 = integer((today-dob)/365.25) label var1 "Age at date of calculation" b gen i var1 = integer((today-dob)/365.25) label var1 "Age at date of calculation" c In both instances (a+b) the values are only kept further on if you issue a saving command: savedata

2. Temporary variables - which are only kept in memory In entry these are defined as SK did:

BEFORE FILE DEFINE var1 ##### DEFINE var2 ##### END

In analysis these are defined : (notice "global") define var1 ##### global

Temporary variables cannot be saved to a rec file unless the content is transferred to a variable saved in a data file. Sometimes we call variables in data files for "fields" in contrast to what is only in memory. SK could argue that define should do the same in analysis and entry to avoid the confusion.

In other words now SK can get the results of the calculation saved for analysis by:

Add to the qes file aged Age in days ##### agem Age in months ####

chk file. remove the "define" in before file but keep the calculation "let" in the "after entry" block and add this

aged noenter end

agem noenter end

regards Jens Lauritsen EpiData Association