TIMED MEASUREMENTS The timed nature of specimens is dealt with in the history and event model of the RM and available in the archetype editor. This deals with timed measurements and interval measurements. The idea of a 21 day progesterone is covered in state information relating to the time since the last menstrual period - BUT there is still the idea of an untimed sequence of events where the order is critical. There are also sequenced events when it comes to looking for stool microscopy, occult blood - but these are reported separately and really are administrative rather than of the nature I will describe here.
The best examples of this seem to occur in sampling - three samples of CSF - the first, second and third - or shavings for histology looking for depth of tumour. There are more, such as respiratory function tests with particular challenges - and timing is not an issue. These occur one after the other but the sequence is the only thing that is important - not the time - and time would probably be made up. The question is, how do we deal with this. I think we have two choices: 1. We recognise this is a sampling issue and there should be a label on each sample which is transfered to the report - we have sample 1, 2 and 3 with three separate microscopies and cultures in a single composition. This would get around the confusion of trying to deal with this as a timing issue - it would work for any sampling including location. We do not want to compare these CSF samples in queries as equals but we would have some sort of label associated. So, the sample label and order might be part of this - in the request and then in the result. I guess this goes on at the moment. 2. We have a sequence idea in the event model, by using the offset but having 'sequence' as the unit rather than time. This would mean that people did not have to enter spurious times in the data and name the event as Sample 1, which could be misleading. Comments? Cheers, Sam ____________________________________________ Dr Sam Heard Ocean Informatics, openEHR Co-Chair, EHR-SIG, HL7 Chair EHR IT-14-9-2, Standards Australia Hon. Senior Research Fellow, UCL, London 105 Rapid Creek Rd Rapid Creek NT 0810 Ph: +61 417 838 808 sam.heard at bigpond.com www.openEHR.org www.HL7.org __________________________________________ - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
