Incorrect LOINC codes in d_labitems

Is there a plan to correct the possibly incorrect LOINC codes in d_labitems (by either replacing the incorrect LOINC codes or creating a new column in the table)? The itemids of MIMIC-IV appear to be the same as those from MIMIC-III, and (by random sampling) most of the LOINC codes haven't changed.

I first want to say that correct LOINC codes are important in this project. While a hospital system's EMR probably doesn't care about LOINC codes much because it doesn't really affect the EMR's internal operation, the LOINC codes become more important when they are used for database analysis--they allow researchers to use lab based algorithms on multiple databases.

For MIMIC-III, I looked at the separate NLM LOINC code determinations (which were provided separately from the MIMIC-III database), and then ran the LOINC codes through my own validator. Overall, I detected that about 75 of the rows (out of 753 rows total) in d_labitems had likely incorrect LOINC codes. Of the 75 likely incorrect LOINC codes, the NLM specified codes was correct in about 62 of them (about 80%). Most of these are instances where the EMR LOINC codes used the wrong LOINC property. For example, itemid of 50960 has a LOINC code of 2601-3. This is the LOINC code for serum magnesium in units of moles/volume (property=substance concentration). The correct code should be 19123-9, which is serum magnesium in units of mass/volume (property=mass concentration). This is compatible with the only reported unit in the labevents for this (mg/dL). A few of the incorrect codes are WAY off for other reasons. A lot of the other likely-incorrect codes were not as clear (based on the MIMIC-III data available).

I think it would be useful to create a new column in d_labitems that represents the revised LOINC code. This way, the original LOINC code would still be preserved (useful in the cases where the most correct LOINC code is unclear).