On Tue, 2003-08-05 at 07:27, Thomas Beale wrote: > Tim Churches wrote: > > >On Tue, 2003-08-05 at 07:01, Thomas Beale wrote: > > > > > >>right. This is exactly the openEHR approach. Have a look at the > >>reference models, including for demographics > >>(http://www.openehr.org/Doc_html/Model/Reference/demographic.htm), and > >>you will see that is exactly what the approach is. Actually, the > >>demographics model is intended to work for all care domains. Undoubtedly > >>it has to be improved before it does that, but that's what > >>implementation and testing are for... > >> > >> > > > >Why are parties versioned? Human cloning is banned in most countries, > >and so far unsuccessful in the rest. Maybe for a Raelian EHR? Seriously, > >the attributes of a party change, but the identity of the party remains > >the same? Or is versioning just an easy way of incorporating the time > >domain into the model? If so, it is easy, but inefficient. > > > the attributes do change. The point is to know what the party looked > like at any given point in time in the past - so if you reconsititute > the EHR for 2 years ago, you also get the 2-years ago view of all the > demographic entities mentioned in it, including the patient. Without > versioning of demographic information, medico-legal investigations into > past states of the EHR can't work...
Yes, yes, of course, that is taken for granted. > > Not sure what you mean by "inefficient".. Well, I have changed my address several times during my life, but not my sex or my name. This can be modelled by either keeping an address history within my demographic record (that is, explicitly modelling the time domain), or by keeping timestamped versions of my entire demographic record. openEHR seems to adopt the latter approach. That approach is less efficient space-wise, but that hardly matters these days. It is more efficient if the (medico-legal) query is "what was my demographic record at date yyyy-mm-dd?" Much less efficient if the query is "how many times did I change my address?". Very, very inefficient if the query is "what is the mean number of address changes in the entire population?". I am thinking from an aggregate epidemiological POV, not a clinical/medico-legal individual patient POV. But then, satisfying the former POV is what data warehouses, populated from EHRs, are for... Tim C > > - thomas > > > - > If you have any questions about using this list, > please send a message to d.lloyd at openehr.org -- Tim C PGP/GnuPG Key 1024D/EAF993D0 available from keyservers everywhere or at http://members.optushome.com.au/tchur/pubkey.asc Key fingerprint = 8C22 BF76 33BA B3B5 1D5B EB37 7891 46A9 EAF9 93D0 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20030805/4018c311/attachment.asc>
