Rodrigo, I am jumping in late in the The DV_QUANTITY (or technically the DV_ORDERED abstract class) data type represents the reference range specified by the lab using the the normal_range relationship. There is also other_reference_ranges to represent all possible reference range differentiated by various patient context such as pregnant female, etc. The normal_range is used for the range that is applicable to this subject. The is_normal method in DV_ORDERED allows it to compare the actual quantified magnitude with the normal range and return an indicate that it is normal or not. You can use this to raise your alert of abnormal results when is_normal returns false. The XML schema published with openEHR Release 1 actually went one step further and I believe it is a necessary addition to the reference model. It treats is_normal as an attribute and allows you to optionally specify the value of is_normal rather than it being calculated. This is useful when transforming HL7 Lab data into openEHR and Pathologists seem to not like downstream manipulation and interpretation of raw data in case the original data is mis-interpreted. This has lead to particular best-practice in Australia where lab data provided in atomic form also needs to have a full text report included along with the atomic data which should be used for display and audit purposes. Even though openEHR support an indicator for is_normal this still stops short of lab data provided in HL7 messages. The abnormal flag in HL7 lab results is coded with values such as L, H, LL, HH, N, A, AA, etc indicating more than not normal but which direction and the degree of abnormality. When transforming this source data into openEHR we loose this additional information about abnormality. I would suggest that there needs to be an additional attribute on DV_ORDERED that represents this interpretation of abnormality. By providing this new abnormality code attribute the is_normal can remain as a method and additional guidance can be provided for that method to derive its value from the abnormality code attribute value if it exists otherwise compare the quantified magnitude with the normal range. Regards Heath Heath Frankel Senior Interoperability Consultant Ocean Informatics
Ground Floor, 64 Hindmarsh Square Adelaide, SA, 5000 Australia ph: +61 (0)8 8223 3075 fax: +61 (0)8 8223 2570 mb: +61 (0)412 030 741 email: <mailto:heath.frankel at oceaninformatics.biz> heath.frankel at oceaninformatics.biz _____ From: [email protected] [mailto:owner-openehr-technical at openehr.org] On Behalf Of Rodrigo Filgueira Sent: Thursday, 7 September 2006 5:19 AM To: openehr-technical at openehr.org Subject: Re: Normal and other ranges Thank you all for your answers. It's clear to me that Archetypes are not the place. And that openEHR does not offer any particular solution. But since we are developing a system which should provide alerts and messaging for abnormal results and "dangerous" combinations of data values, we need to solve it in some way. Any links or reference material on possible approaches to this issue would be very welcome. thank you all again Dipak Kalra wrote: Dear All, Pathologists and laboratory message standards developers have over many years made clear to me that it is always good practice to include the applicable normal range with individual instances of observed values, since those ranges are not fixed across measurement methods, devices, organisations or over time. Published reference ranges in clinical textbooks etc. are only a guide for those tests in which the variation is nowadays quite small. For this reason, right from Synapses days - a decade ago! - , we have not sought to put reference ranges into the archetype specification, but (as Tom has stated) only to ensure that the archetype caters for the inclusion of reference range instances along with the observed value(s). With best wishes, Dipak ________________________________________________________ Dr Dipak Kalra Clinical Senior Lecturer in Health Informatics CHIME, University College London Holborn Union Building, Highgate Hill, London N19 5LW Direct Line: +44-20-7288-3362 Fax: +44-20-7288-3322 Web site: <http://www.chime.ucl.ac.uk/> http://www.chime.ucl.ac.uk _____ _______________________________________________ openEHR-technical mailing list openEHR-technical at openehr.org http://www.chime.ucl.ac.uk/mailman/listinfo/openehr-technical -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openehr.org/mailman/private/openehr-technical_lists.openehr.org/attachments/20060907/0d8fb7f1/attachment.html>
