So Many Books, So Little Time- Part 2

ICD-9-CM Has Procedure Codes?

In part two of my blog series about coding systems, I'd like to present ICD-9-CM, Volume 3. If you've taken classes that are preparing you to take the CPC exam, it might be news to you that ICD-9-CM has three volumes. Or procedure codes. So that's it: volume 3 of ICD-9-CM is procedure codes. 

Hospitals Use It

In part one of this series, I mentioned that HIPAA defines which code sets are used for each health care setting. Volume 3 ICD-9-CM codes are only mandated for hospital inpatient claims. They are a major factor in the determining DRG assignments, which drive hospital inpatient payments. 

Some hospitals also assign ICD-9-CM volume 3 codes for hospital outpatients as well. This is solely for data collection purposes but the codes get "scrubbed" off the outpatient bill and don't go to the insurance company. ICD-9-CM codes may be used to analyze volume of a particular type of procedure performed either as inpatient or outpatient. For example, most appendectomies are performed as outpatients, but if there are complications, a patient may need to be admitted as an inpatient. Hospitals often pull procedure volume for physician credentialing or planning purposes (e.g., to determine if a new specialty unit or more operating rooms are needed).  As a coding manager, which was a long time ago, I wrote reports that pulled data based solely on ICD-9 codes. We didn't use CPT codes to pull data at all at that time. 

Why You May Have Never Heard of It

If you've never heard of volume 3 codes in school, then it's likely that you are taking a coding course for physician coding and billing. Physicians don't use volume 3 of ICD-9. But as mentioned above, hospital coders are using it and if a hospital requires its coders to assign ICD-9 codes on outpatients, they are coding procedures using both ICD-9 and CPT procedure codes. That isn't as complex as it sounds because most hospitals use encoder software that has a crosswalk between the two code sets. Unfortunately, any time you try to map from one code set to another, there can be errors. If they were easily translatable, we wouldn't need two code sets!

Here's another critical tip: if you are buying ICD-9-CM code books, it can be super confusing because there are various publishers and lots of code books with different-yet-similar titles.  If you purchase an ICD-9-CM code book for physicians, it will have only volumes 1 and 2.  If you buy ICD-9-CM for hospitals, you get all three volumes, or the complete ICD-9-CM code set.

What the Codes Look Like

The code format of volume 3 ICD-9-CM codes is different from other code sets with two numeric digits followed by a decimal point and then one or two more numeric digits. The code category ranges are 00-99. It's the most straightforward of all of the HIPAA code sets. 

Some examples of volume 3 codes are:

• 47.0, Appendectomy
• 36.97, Insertion of drug-eluting coronary artery stent(s)

Commentary on ICD-9 Volume 3 and Argument for ICD-10

If you weren't trained on ICD-9-CM procedure codes, let me tell you, you aren't missing much. It is the least robust of all of the coding systems. There just simply aren't enough three to four-digit codes to keep up with rapidly evolving healthcare technology. We have run out of available codes. This is my biggest argument for ICD-10 implementation. I hate to say that we can live without a diagnosis code update, but in comparison to procedures, the need isn't as great. We absolutely need a new procedural coding system for ICD in order to keep up with emerging technologies. Plus - and this drives the OCD coder in me crazy - there are hernia repair codes in the eye procedure chapter because it's the only chapter with available codes!  

If you were trained in CPT first and have to learn ICD-9 volume 3 codes, you may find it very difficult, but only because you are trying to find codes as specific as CPT. You will be disappointed because ICD-9 codes aren't that specific. While there are appendectomy codes in CPT for open and laparoscopic approaches, ICD-9 appendectomy codes don't differentiate between open and scope procedures. 

Who Needs to Learn it?

If you're planning to take a certification exam, here are the certifications that have traditionally tested on volume 3 ICD-9-CM codes, but keep an eye on test details for the testing switch over to ICD-10:

• CCA (Certified Coding Associate) from AHIMA
• CCS (Certified Coding Specialist) from AHIMA
• CIC (Certified Inpatient Coder) from AAPC (new)

The COC (Certified Outpatient Coder), formerly called the CPC-H (Certified Professional Coder Hospital-based) does not focus at all on ICD-9 volume 3 codes. It does focus on hospital-related CPT codes and, of course ICD-9 diagnosis codes because we all use that. 

The bottom line on volume 3 codes, in my opinion, is that it is a coding system with a limited shelf life that isn't worth learning at this point in the game if we really move forward with ICD-10-CM/PCS in October (or unless you are planning to take one of the above-mentioned certification exams before ICD-10 is implemented).  There are enough existing coders to focus on the ICD-9 back work that will be involved after ICD-10 implementation and since this code set is only required for hospitals, it affects a pretty small population of coders overall.  But hey, at least you now know what it is and can have an intelligent conversation about it. 

Next up: Level I of HCPCS (AKA CPT)...

What the Heck is a DRG? And Why Should I Care About Case Mix?

So you want to be a coder. And not just that, you want to be a hospital coder because, on average, they make more money than physician coders. And you don't just want to be a hospital coder, you want to be an inpatient hospital coder because then you get to look at the whole chart and piece together the patient's clinical picture. If this is your goal, then everything you need to know you will not learn in school. And that's mainly because there is so much to learn and practical experience is key.

Most of all, if you want to be an inpatient coder, you need to know diagnosis-related groups (DRGs) because in hospitals, it's all about DRGs and case mix - and compliance. If you have no idea what I'm talking about, fear not - here's a primer on DRGs! I wish I could say I cover it all here, but this is just a beginning!

What is a DRG?
The ICD-9-CM coding system contains about 16,000 diagnosis codes and ICD-10-CM contains over 68,000 codes. Imagine trying to determine a payment amount for each individual condition. And that doesn't include accounting for procedures. The most logical solution is to create a system that allows for broader classification of conditions and services for easier comparison and assignment into payment categories. DRGs were created for this purpose. I look at DRGs as a way to "organize the junk drawer" where patients are grouped into different categories based on similar conditions and cost to treat the patient.

History
DRGs were first developed at Yale University in 1975 for the purpose of grouping together patients with similar treatments and conditions for comparative studies. On October 1, 1983, DRGs were adopted by Medicare as a basis of payment for inpatient hospital services in order to attempt to control hospital costs. Since then, the original DRG system has been changed and advanced by various companies and agencies and represents a rather generic term. These days, we have various DRG systems in use - some proprietary and some a matter of public record - all of which group patients in different ways. Two of the main DRG systems currently in use are the Medicare Severity DRG (MS-DRGs) and 3M's All Patient Refined DRGs (APR-DRGs). Different DRG systems are used by different payers.

How to Get a DRG
All DRG systems are a little different, but the basic premise is the same. DRGs are based on codes. In effect, DRGs are codes made up of codes. The following elements are taken into consideration when grouping a DRG:

• ICD-9-CM diagnosis codes
• ICD-9-CM procedure codes
• Discharge disposition
• Patient gender
• Patient age
• Coding definitions as defined by the Uniform Hospital Discharge Data Set (UHDDS) - in other words, the sequence of codes on the claim

Back in the 80s, DRGs were grouped manually using decision trees. These days, DRGs are grouped with the touch of a button and DRG groupers are a big part of encoding software. But I would be doing you a disservice if I didn't at least give you an idea of the grouper logic. As I mentioned, there are different DRG systems and probably the most popular is the MS-DRG system, so I will explain how MS-DRG grouper logic works.

MS-DRG Grouper Logic
The first step in assigning an MS-DRG is to classify the case into one of the 25 major diagnostic categories (MDC). These MDCs are based on the principal (first) diagnosis and, with a few exceptions, are based on body systems, such as the female reproductive system. Five MDCs are not based on body systems (injuries, poison and toxic effect of drugs; burns; factors influencing health status (V codes); multiple significant trauma; and human immunodeficiency virus infection). Organ transplant cases are not assigned to MDCs, but are immediately classified based on procedure, rather than diagnosis. These are called pre-MDC DRGs.

Once a case has been assigned into an MDC (with the exception of the transplant pre-MDCs), it is determined to be either medical or surgical. Surgical cases require more resource consumption (that's industry speak for "costs more!"), so they must be separated from the medical cases. If there are no procedure codes on the case (e.g., a patient with pneumonia may have no procedure codes), then it's simple - it's a medical case. But if the patient had a procedure, that procedure may or may not be considered surgical. For example, an appendectomy is quite clearly a surgical procedure. But something like suturing a laceration is not. It's all based on resource consumption - the cost of performing the procedure. In general, anything requiring an operating room is surgical.

Quick sidebar here - this is why skin debridement is such a hot topic in the world of coding compliance. Nonexcisional debridement (code 86.28) groups as a medical case. However, excisional debridement (code 86.22) groups as a surgical case and the change in reimbursement is rather drastic.

Okay, so now that we have our MDC and a designation as medical or surgical, we need to look at the other diagnoses on the claim. Right now, Medicare is able to process the first 9 diagnoses on the claim (even though 18 are reportable). These other diagnoses, depending on their severity, may be designated as complications and comorbidities (CCs) or major complications and comorbidities (MCCs). Medicare maintains lists of CCs and MCCs and updates them annually. CCs and MCCs are conditions that have been identified as significantly impacting hospital costs for treating patient with those conditions. For example, it's been determined that congestive heart failure without further specification does not significantly impact costs and it is not a CC/MCC. However, patients with chronic systolic or diastolic heart failure do have slightly higher costs, so those conditions are CCs. More so, patients with acute systolic or diastolic heart failure have even higher costs, so they are designated as MCCs. Are you beginning to see how slight changes in a physician's diagnostic statement impact coding and thus payment?

DRG Weights
Okay, so we know the MDC, whether the case is medical or surgical, and whether or not there are any CCs or MCCs. How does that translate into reimbursement? Well, if you're using an encoder (and if you code for a hospital, you will), you hit a button and presto! You have a DRG with a relative weight. Now if only you knew what that relative weight meant. The DRG relative weight is the average amount of resources it takes to treat a patient in that DRG. Huh?

Let me demonstrate. The baseline relative weight is 1 and represents average resource consumption for all patients. Anything less than 1 uses less than average resources. Anything above 1 uses more than average resources. So let's compare some respiratory MS-DRGs:

• MS-DRG for lung transplant has a relative weight of 9.3350
• MS-DRG for simple pneumonia (no CC/MCC) has a relative weight of 0.7096
• MS-DRG for chronic obstructive pulmonary disease with an MCC has a weight of 1.1924

You can see how different combinations of codes lead to different MS-DRGs with different relative weights. In order to convert that into monetary terms, we multiply the relative weight by the hospital base rate. Now I'm sure you want to know how to get that hospital base rate. Me too. Well, up to a point. The base rate is exclusive to each hospital and takes a lot of historical, facility-specific data into account, like what they've been paid in the past, whether or not they are an urban or rural hospital, and how much the hospital pays out in wages. That's just more math than my poor little head can comprehend! So for the purposes of this exercise, let's pretend like this hospital - we'll call it Happyville Hospital - has a base rate of $5000. So if we multiply the relative weights above by $5000, our reimbursement for those cases, respectively, is $46,675, $3,548, and $5,962.

Case Mix
You just might be asked in an interview if you understand case mix. It's a good indication of whether or not someone really understands DRGs. And I have to admit, in my sometimes sadistic manner, I like seeing that look of glazed-over confusion on someone's face when I bring up case mix. But case mix is simple. It's the average relative weight for a hospital. So get out a big piece of paper for your hospital and start writing down the relative weights for every single case and then divide to get your average. Okay, so it's computerized now. But that's all case mix is - an average.

In the industry, we officially refer to case mix as the type of patients a hospital treats. Let's say at Happyville, we have a high volume of transplant cases plus a trauma center and a well-renowned cardiac program. These are all highly weighted types of cases and our overall case mix will be higher than say, Anytown Hospital down the street that has no trauma center, no transplant program, and basic cardiac services (they transfer all their serious cardiac cases to Happyville!). Happyville's case mix will be higher than Anytown's.

As a coder, you don't need to know what your specific hospital's case mix is at any given time. But knowing what impacts case mix is an indication that you know your stuff. First and foremost, case mix fluctuates. Most hospitals monitor case mix on a monthly basis because changes in case mix are a precursor to changes in reimbursement. Of course your CFO wants case mix to continue to rise, but that could be a red flag. And he certainly doesn't want case mix to fall. If case mix begins to decrease, the first place hospital administration usually looks is coding - after all, case mix is based on DRGs, which are based on codes. But there are lots of things that can impact case mix and many of them have nothing to do with coding, such as:

• The addition or removal of a heavy admitting physician - especially specialty surgeons
• Opening or closing a specialty unit
• Changes in a facility's trauma level designation
• Movement of cases from the inpatient setting to outpatient, and
• Anything else that impacts the type of services the hospital provides

Your Life as an Inpatient Coder
As an inpatient coder your job is to make sure you get all the codes on the claim in the correct order so that the accurate DRG is assigned and the hospital gets paid appropriately. When I put it that way, it sounds so easy! The reality is, with more and more patients being treated as outpatients, those who are admitted as inpatients are sicker than they've ever been. And sicker means harder to code. For instance, the patient comes in with shortness of breath and the final diagnosis is acute exacerbation of COPD, stapholococcal pneumonia, and respiratory failure. How you code and sequence the case will determine the appropriate DRG and reimbursement. The good news is, you'll have an encoder to help you model the DRGs and see what pays what. The bad news is, you have to paw through the medical record to determine the true underlying cause of that shortness of breath.

So are you ready for the challenge? Are you ready to apply DRGs?