On 18/03/2011 12:04, Ian McNicoll wrote: > Thanks Peter / Thomas, > > This is quite important and I had not appreciated the limitations on > the use of partial dates with DV_DATE_TIME. I would agree that > DV_DATE_TIME + DV_TIME would be very unusual but it is a very common > requirement in clinical systems to be able to supply a vague date - > year only or year + month and from what you say DV_DATE_TIME will not > allow this, unless an hour is also supplied. > > I am struggling to understand the reason for this restriction in ISO > 8601:2004 - if the date is vague, what is the point of having any time > at all!! Though I suppose the use case might be - "It was a cold dark > December night and the clock has just struck 23:00".
I guess the idea is 'I had a migraine at about 10am on Sunday 1st Feb'.... > > Having to add a DV_DATE constraint seems horribly clumsy. Perhaps we > just need to make it clear than in implementation, some sort of dummy > time is added. In clinical terms this will always be > meaningless except in exceedingly rare circumstances. > > * > * I am not sure. I think that if one investigates closely the questions whose answers could really be a time-point (i.e. DV_DATE_TIME), they would not intersect that much with questions that could be answered with just a date - partial or not. I think that where the questions are like: doc: so what date was this? patient: last monday, so,... hm... the 14th March doc: and what time? patient: oh, just after feeding the baby, about 2pm I would guess that the 'what time?' question is only asked if the time is relevant to the problem, or recurrent patterns of it; most likely because it is linked to some real world event (e.g. feeding baby, drinking alcohol). So I think that the actual data points here are something like: date of occurrence: DV_DATE time of occurrence: DV_TIME linked event: DV_TEXT rather than a timestamp. - thomas -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20110318/78c8635c/attachment.html>
