Yesterday, I found another jewel of where this madness leads to. It is about the development of the "Ebola Therapeutic Area User Guide", and how the observations "highest temperature in the last 24 hours", "highest pulse in the last 24 hours" and "lowest blood pressure in the last 24 hours" should be represented as SDTM. Here is a small part of the very long discussion from the CDISC wiki:
In the post on the SDTM wiki, it is suggested that VSTSDTL (Vital Signs Examination Detail) be added and used. The contents of it would essentially be free text which is not so well understandable by machines.
However, there is a very simple solution!
"Maximum in the period of 24 hours" is defined by LOINC. So I was not surprised that I could find exact LOINC codes for the four cases mentioned. A simple search (<5 minutes) in the LOINC database, led to following results:
- Highest temperature in 24 hours:
LOINC Code: 8315-4
LOINC (short) Name: Body temperature:Temp:24H^max:XXX:Qn
LOINC Long (common) Name:
All we then need to do is to add these LOINC codes in VSLOINC, and we are ready. If it were not mandated by the SDTM-IG, we could even leave VSTESTCD and VSTEST out, as the value of VSLOINC containing the LOINC code has the full and 100% correct and exact description of the test that was performed. The details of what the code means can be easily retrieved by any modern tool by e.g. using RESTful web services.