sdtm_ta.RdTrial Arms data frame - One record per planned Element per Arm
sdtm_taa data frame with 8 rows and 10 columns. See https://github.com/SafetyGraphics/safetyData/blob/main/data-raw/sdtm/README.md for more details and full data specification. Columns:
 STUDYID text - Study Identifier
 DOMAIN text - Domain Abbreviation
 ARMCD text - Planned Arm Code
 ARM text - Description of Planned Arm
 TAETORD integer - Order of Element within Arm
 ETCD text - Element Code
 ELEMENT text - Description of Element
 TABRANCH text - Branch
 TATRANS text - Transition Rule
 EPOCH text - Epoch