I am not an expert, but my interpretation of these two data sets is…
1) BACKMEDS is a better formatted and more focussed data set, listing key medications (KEYMED) which are more directly relevant to dementia interventions.
2) For example, the KEYMED field is defined as: 0=None of the above; 1=Aricept; 2=Cognex; 3=Exelon; 4=Namenda; 5=Razadyne; 6=Anti-depressant medication; 7=Other behavioural medication, according to ADNI’s data dictionary.
3) BACKMEDS does not seem to include records for ADNI1.
4) RECCMEDS is a more detailed and ‘messier’ listing of all sorts of things, such as vitamin supplements (CMMED).
5) According to the data dictionary, RECCMEDS includes the BACKMEDS, at least for ADNIGO and ADNI2, but many entries look like free text entry.
6) RECCMEDS includes something about prescription reason (CMREASON)
7) RECCMEDS does have records for ADNI1.
So…it might be that BACKMEDS was derived from RECCMEDs, but probably not vice versa.
HTH,
Dave