The third most reimbursement-lowering impact across nearly all DRGs, after Malignant hypertension and Uncontrolled diabetes, concerns ICD-9 codes 296.20 Major depressive affective disorder, single episode, unspecified and 311 Depressive disorder, not elsewhere classified.
296.20 Major depression, is a CC, so it will increase reimbursement for any case it is attached to – sometimes dramatically. 311 Depression NEC, is not. 311 is coded on about 1 in every 20 records – 296.20 only about a tenth as frequently.
Both codes translate to F32.9, Major depressive disorder, single episode, unspecified, in ICD-10. This means that if nothing changes between now and October 1, 2014, two distinct types of patients, those who are diagnosed with major depression, and those who are diagnosed with unspecified depression, will be captured in the ICD-10 data using the same code. How should F32.9 be defined in MS-DRGs? Should it be a CC or not? Like 296.20, with whom it shares an almost-identical code title, or like 311, which is ten times more frequent? Minimizing the impact of the shift to ICD-10 dictates the latter – better to lose the CC on 5 out of every thousand records than add a CC to 50.
But wait, you say, coders are not going to start calling every depression “Major” in ICD-10. Surely they’ll code what is now Depression NEC as something else, allowing F32.9 to represent only what 296.20 used to, and thereby keep its CC status. I initially made that same mistake – a common one among those of us who are not coders but users of codes in modeling and analysis – assuming that the meaning of a code is fully represented by its code title.
Coders know that the definition of a code is distributed across the coding system’s two official documents: the Tabular and the Index. New coders are trained to start in the Index and follow it to the Tabular and read all the notes there before settling on a code. Those of us who start with a code and need to know what it means have to use the same process, but in reverse. So I’ve looked up F32.9 using 3M’s Code Translation Tool, which has a “reverse index”, showing me all the index entries that would lead a coder to F32.9. (Were it not that flogging 3M products in these blogs is frowned upon, you’d be hearing a lot about CTT, as it is the principal thing I’ve been working on these last three years.)
I find that both
Depression (acute)(mental), major
among many others, lead the coder to F32.9. Once there, she sees, among the alternate terms listed for the code:
Depressive disorder NOS
Major depression NOS.
The “Major” in the code title for F32.9 is misleading. We have to ignore it. The CC has to go.
Ron Mills is a Software Architect for the Clinical & Economic Research department of 3M Health Information Systems.
Want to learn more about streamlining the ICD-10 translation process to help prepare your organization now for a successful ICD-10 implementation? Join us on Tuesday, October 23rd at 1:00 p.m. EDT for a close look at the new 3M™ ICD-10 Code Translation Tool (CTT) version 2.1. Registration is now open.