Easy logic to check if OBX-5 is an attachment or not?

Question

Some of the HL7 that I am receiving are only units (i.e. 3.0, 8.7-9.0) or strings (i.e. NEGATIVE, POSITIVE).  Currently my thought is checking the length of the OBX-5 node, but I feel that this is not robust enough.  

Is there a more robust way of checking if OBX-5 is an attachment or not?

 

Thanks!

Answer 1

Since OBX-5 is free text, it can be difficult to extract the content and know what to do with it.

Checking the length is a good start. You could also check for line breaks in that field (~). I would recommend starting with the use cases you have seen come through that HL7 feed.  You can start to code for the most common values, and then add more logic as you come across different types of values.

Answer 2

If these message are being sent to LinkLogic for CEMR or CPS,  the value in OBX-3 should tell you whether or not OBX-5 contains an attachment.

• NO_REF -- OBX-5 contains text (not a reference to an external attachment)
• IMAGE_REF -- OBX-5 contains a reference to an image
• TEXT_REF -- OBX-5  contains a reference to an external document
• OTHER_REF -- OBX-5 contains a reference to externally managed data of unknown type