Hi all,
A few belated comments on Booleans. In my experience there are a few genuine booleans in clinical data e.g. “Is the prostate specimen present Y/N” in the context of histopath . Well it either is or it ain’t. Not much use for null flavours or ‘yes … but’ , but in most circumstances the Yes/No construct is essentially a mangled clinical statement with all the ifs, buts and maybes that implies.
"Is the urine blood-stained-> Yes is equivalent to “Urine bloodstained” and .
"Is the urine blood-stained-> No is equivalent to “Urine not bloodstained”.
It is now my standard practice in virtually all cases to model these clinical booleans as term lists, generally ensuring that the key semantics are carried in the value i.e “Urine blood-stained” , rather than just “Yes” but this definitely annoys developers who without clinical understanding can find it difficult to know how to map the terms to the checkbox or radio-button boolean paradigm in their requirements documents.
It is easy to dismiss this as just ‘a GUI / presentational issue’ but I think that the clinical questionnaire pattern is actually a legitimate if unsupported kind of clinical recording which has been largely overlooed by informatics, and should be acknowleged and supported in openEHR., even if the key undelying paradigm (as for HL7 and SNOMED) is the clinical statement.
So one immediate requirement is for a DV_BOOLEAN to allow term-bindings (including internal atCoded terms to the possible values but I think there is whole world of interesting PhDs to be done on the subject!!