Codes Used in DRG Assignment?

QUESTION

Hi Tech Support,

The PDF is very informative but it appears to be missing explanation of a couple of the output codes. I get ten bits of info but only first eight appear to be documented in the grouper's documentation PDF ("UNIX Embeddable Grouper API": pages 31-32). Those are .......

1. Grouper return code
2. Major Diagnostic category of assigned DRG
3. DRG assigned to patient encounter
4. DRG version number used to assign DRG
5. The weight of the DRG
6. Geometric mean length of stay for DRG
7. PorM flag
8. DRG description

The string I had returned to me by the grouper was....
0^1^57^28^0.9350^0.00^ ^DEGENERATIVE NERVOUS SYSTEM DISORDERS W/O MCC ^1^0

It's the last two fields of "1" and "0" that appear to be undocumented.

The last question I have is regarding the significance of diagnosis codes. When feeding a list of diagnosis codes into the grouper, is there a way to determine which of the diagnosis codes were significant in the grouper's decision making? I ran across something like that on page 22 (section labeled "Output") of the PDF that you folks package with the grouper.

Thanks so much for all of your assistance.

ANSWER

The lack of documentation for these fields is definitely an oversight, thank you for pointing this out. We will include these fields in the updated manual when we release it this coming October.

Those two fields are ASCII-ified bit strings of which codes were used in the DRG assignment. The first field is a string of diagnosis bits and the second string is a string of procedure bits. The strings consist of either an ASCII '1' or an ASCII '0'. A one means "this code was used" and a zero means "this code was not used."

The strings are positional: 1001 means that the first code was used, codes two and three were not but code four was.