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Negative values in Lab test records

CDM Builders
#21

@ericaVoss @Vojtech_Huser @Christian_Reich @Asha_Mahesh @nzvyagina
I’m not sure this is related with what you’re discussing, but I have a question.
One of the results from Heptitis B virus surface Ab (concept_id = 3023421) in our institution is ‘Positive, 85.34’, which means positive for the Ab and value of titer is 85 (Definitely it is not wrong record).

In this case, we records both the value_as_number (85.34) and value_as_concept_id (’+’).
Do we have standardized solution for this, too?

1 Like
#22

@SCYou:

Yes. Use 9191 “Positive”. Or any concepts where standard_concept=‘S’ and domain_id='Meas Value".

3 Likes
#23

Thank you @Christian_Reich, That’s what we’re doing now!

#24

Just updating this thread with the most current recommendation. If you have ideas or more items for the exception list let us know!

RECOMMENDATION
Only allow values for negative measurements (see list below). If you have negative values for positive measurements, then set it to NULL. Negative Measurements 1925-7-Base excess in Arterial blood by calculation 1927-3-Base excess in Venous blood by calculation 8632-2 - QRS-Axis 11555-0 - Base excess in Blood by calculation 1926-5 - Base excess in Capillary blood by calculation 28638-5 - Base excess in Arterial cord blood by calculation 28639-3 - Base excess in Venous cord blood by calculation

NEXT STEP

  1. Work to develop an exception list (e.g. 1925-7-Base excess in Arterial blood by calculation, RANGE: mmol.L:[-2,+2], https://s.details.loinc.org/LOINC/1925-7.html)
  2. Update ACHILLES (@vojtechhuser) to do a warning on non-exempt tests that are negative.
  3. Work with CDM WG to document both the exception list and above text in the VALUE_AS_NUMBER column. https://github.com/OHDSI/CommonDataModel/wiki/MEASUREMENT
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