One of the more recent projects for a client was to export all data from DataFax into CDISC’s Standard Data Tabulation Model (“SDTM”). In this Blog, I want to share some of our experiences with this SDTM export.
Is it difficult? Yes and No. Anybody who has ever worked with DFsas, will understand that this tool is extremely helpful in this. Anybody who has used this tool, knows it versatility. As with most things in life, this strength is also its weakness. Meaning that you have to be very careful with its programming. If you replace
15 SEX "Sex" 16 RACE "Ethnic group" with 16 SEX "Sex" 15 RACE "Ethnic group"
The contents for Sex and Race will be swapped, so a Black Male will ‘turn into’ Caucasian Female.
Anyway, this same feature of exporting Fields by their Field reference (so by a number) is very helpful when exporting to SDTM. Some SDTM Domains are highly Normalized, meaning each item on a CRF page results in the creation of a single record in the SDTM Domain. Examples of these are the “VS” or “QS” Domains. So if you have a single CRF page with a number of different Vital Signs, your SAS job file might look like:
# data1 NORMALIZE DFVISIT "DataFax Visit Number" VSTPTNUM "Planned Time Point Number" VSTESTCD "Vital Signs Test Short Name" VSDTC_D "Date/Time of Measurements" VSORRES "Result or Finding in Original Units" VSORRESU "Original Units" # # Variables from plate ... # RECORDS 123 6 "1" "SYSBP" 8:s 11 "mmHg" 6 "1" "DIABP" 8:s 12 "mmHg" 6 "1" "PULSE" 8:s 13 "BEATS/MIN" 6 "1" "HEIGHT" 8:s 14 "cm" 6 "1" "WEIGHT" 8:s 15 "Kg" 6 "1" "TEMP" 8:s 16 "C"
This same method can off course be used for the “QS” Domain where each individual item (of a Questionnaire) needs to be exported as a single record
