sdtm_ds.RdDisposition data frame - One record per disposition status or protocol milestone per subject
sdtm_dsa data frame with 596 rows and 13 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
 USUBJID text - Unique Subject Identifier
 DSSEQ integer - Sequence Number
 DSSPID text - Sponsor-Defined Identifier
 DSTERM text - Reported Term for the Disposition Event
 DSDECOD text - Standardized Disposition Term
 DSCAT text - Category for Disposition Event
 VISITNUM float - Visit Number
 VISIT text - Visit Name
 DSDTC datetime - Date/Time of Collection
 DSSTDTC date - Start Date/Time of Disposition Event
 DSSTDY integer - Study Day of Start of Disposition Event