ICD-9-CM procedures from the State Emergency Department Databases (SEDD) are retained in the data elements PR_ED1 to PR_ED9. The first listed procedure (PR_ED1) may not be the principal procedure; it may just be the first listed procedure on the ED record.

While nine ICD-9-CM procedures per ED event are retained in the NEDS, the number of code fields populated varies. While some States report more than the nine ICD-9-CM procedures, less than 2% of all ED records report more than nine procedure fields. The data element NPR_ED lists the number of ICD-9-CM procedures reported on the original SEDD record.

The original value of the ICD-9-CM first listed procedure (PR_ED1), whether blank or coded, is retained in the first position of the procedure vector. Starting at the first secondary procedure (PR_ED2), the procedures are shifted during HCUP processing to eliminate blank secondary procedures. For example, if PR_ED2 and PR_ED4 contain non-missing procedures and PR_ED3 is blank, then the value of PR_ED4 is shifted into PR_ED3. Secondary procedures are never shifted into the first listed position (PR_ED1).

Validity and consistency checks for the procedure are consistent with all other HCUP databases.