Hello, 

When it comes to  xsi:type="CD" or xsi:type="PQ", when there is no result present or if the result is null (default value of the column which stores the result), we have an option to print  nullFlavor="NI". 

However, when it comes to  xsi:type="ST", how is one supposed to handle this? Should we be taking the same approach as for CD/PQ and print nullFlavor="NI"?

I did look into the HL7 guide (CDAR2_IG_QRDA_I_R1_STU5.3_2021NOV_Vol2), didnt find anything there. 

Can you please give us some guidance on this?

Example here is this:

Measure is CMS124v12. HPV lab test performed. As per measure specs ANY result type or value satisfies the criteria, but, a result is required. For whatever reason, although the lab test is performed, there is no result value documented but the result type is 'ST' a string result. How am i to handle this.