integration MIMIC-ED with MIMIC-Hosp

[MEladawi]

I am focusing on using MIMIC-ED in my research as a standalone dataset. However, I wanted to confirm that the following data in MIMIC-ER is sufficient and I don't need to link to MIMIC-Hosp:

1. Are all the medications administered in the ED included in pysix? or I have to integrate the other tables (emar, prescription, …)? I did a quick check and it looks like very few patients in my population have emar records.
2. Re: diagnosis, is it safe to use diagnosis table in MIMIC-ED alone for patients in the ED? I noticed differences between the codes in this table vs the diagnosis_icd in MIMIC-Hosp, which one is the gold standard? Or are the codes MIMIC-ED for the reason the ED admission and the ones in MIMIC-Hosp are the diagnoses observed during the stay. If so, why would I find ICD codes in ED with seq_num 1 (main reason for ED admission) and not included in diagnosis_icd?

Thanks for the help.