sdtm_mh.RdMedical History data frame - One record per medical history event per subject
sdtm_mha data frame with 1818 rows and 19 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
 MHSEQ integer - Sequence Number
 MHSPID text - Sponsor-Defined Identifier
 MHTERM text - Reported Term for the Medical History
 MHLLT text - Lowest Level Term
 MHDECOD text - Dictionary-Derived Term
 MHHLT text - High Level Term
 MHHLGT text - High Level Group Term
 MHCAT text - Category for Medical History
 MHBODSYS text - Body System or Organ Class
 MHSEV text - Severity/Intensity
 VISITNUM float - Visit Number
 VISIT text - Visit Name
 VISITDY integer - Planned Study Day of Visit
 MHDTC date - Date/Time of History Collection
 MHSTDTC date - Start Date/Time of Medical History Event
 MHDY integer - Study Day of History Collection