Home Health ICD-9/ICD-10 Alert

Case mix codes bring greater scrutiny, experts warn.

Is your ICD-9 therapy coding audit proof? The HHS Office of Inspector General and home health fiscal intermediaries are cracking down on therapy claims errors this year, so now's the time to protect your agency from denials and audits with the most accurate coding possible.

The facts: In a recent probe review of 80 claims with 10 to 15 therapy episodes for patients in their second episodes, Regional Home Health Intermediary (RHHI) Cahaba GBA found a 25 percent error rate. Cahaba found fault with the diagnosis coding in one-third of the denied claims. As a result of its findings in this probe, Cahaba will initiate an ongoing widespread review for medical necessity including compliance with the Centers for Medicare & Medicaid Services'(CMS) guidelines, contractor Local Coverage Determinations, and correct billing and coding, the RHHI says in a medical review notice.

Tip Number 1: Don't Let Case Mix Drive Coding

Cahaba found several instances of incorrectly assigned case mix codes in the claims they examined during the review.

For example: Agencies chose the case mix code 781.2 (Abnormality of gait) when the non-case mix code 719.7 (Difficulty in walking) was more appropriate.

Another example: Agencies chose a higher-paying case mix code  such as 434.91 (Cerebral artery occlusion, unspecified with cerebral infarction) or Parkinson's disease (332.x) when the lower-paying case mix code of 781.2 was really the main reason for treatment, Cahaba points contends. 

When using a condition such as Parkinson's disease as a primary diagnosis, agencies should document an exacerbation or change in this condition, which is usually reflected by medication or treatment changes. The patient record should also show a "holistic approach" involving more than one skilled discipline, the RHHI notes. 

Therapy documentation reflecting gait training and no other treatments points to a diagnosis of abnormality of gait, says one coding expert.

"People forget there's an entire code book; they just look for the codes that give you the case weight," says physical therapist Cindy Krafft, director of rehabilitation for OSF Home Care based in Peoria, IL.

Keep in mind: The RHHIs will look more closely at claims that include case mix codes because these claims cost them more money, cautions consultant Sparkle Sparks, MPT, HCS-D, COS-C, with Redmond, WA-based OASIS Answers Inc.

Tip Number 2: Don't Overuse Physical Therapy, Abnormality Of Gait

Constantly turning to the same codes to support therapy is another mistake. Many coders tend to overuse V codes for therapy, says Krafft. There are agencies whose number one diagnosis for the last fiscal year was V57.1 (Other physical therapy), she notes. V57.1 "is not really a medical diagnosis" and doesn't explain what problem home health is addressing for the patient, cautions Krafft.

Watch out: If you're overusing certain V codes, this can cloud your agency's understanding of its patient population, warns Krafft. An agency whose reports show physical therapy as its number one diagnosis will have a difficult time assessing disease management or looking at outcomes for a particular population, she says.

Abnormality of gait is another over-used diagnosis, says Krafft. Sometimes coders use abnormality of gait when the condition they are really dealing with is in the exclusions list on the code, warns a coding expert. For example, category 781.x (Symptoms involving nervous and musculoskeletal systems) excludes lower back pain.

"If we say every single patient in home health has [abnormality of gait], we run the risk that eventually it's going to be taken off of the list for additional reimbursement," says Krafft. Over-use of a particular case mix code could lead regulators to consider the condition a routine factor of care, she adds. 

"There are many more codes out there that support therapy, and they're not being used," says Sparks. Therapists study comprehensive disease processes, not just symptom management, she points out. Believing that physical therapists and occupational therapists are  concerned only with mobility issues, functional deficits, and energy conservation, and that speech therapists are focused only on speaking and swallowing doesn't appreciate all that therapists can do, she says.

Tip Number 3: Don't Rely On Cheat Sheets

There really isn't a "hit list" of codes that support therapy, says Krafft. Start expanding the codes you use to support therapy by reviewing your fiscal intermediary's local coverage determination, she says. 

Visit your FI's web site, download its Local Coverage Determination, and take a look at the list of codes that support medical necessity, recommends Sparks. "If you're trying to justify the cost of therapy, you need to know about the criteria used by the people paying the bill," she says.

Caution: But don't let your FI's LCD limit the accuracy of your coding, advises one coding expert. If you look at Cahaba's LCD for physical therapy, you'll see a list of diagnoses that support medical necessity, she says. But look under the heading for diagnosis codes that do not support medical necessity, and there's nothing listed, she points out. 

If the patient needs therapy and you're providing one of these therapy modalities, provided your documentation is good enough, it's going to be covered, says the expert.

Note: The Cahaba medical review notice is at www.iamedicare.com/Provider/newsroom/whatsnew/20060126_probe2.htm.