Mitigating the Risks Involved with High-Risk Diagnosis Groups

By AGS Health

August 29, 2023

The Office of the Inspector General (OIG) has set its sights on Medicare Advantage plans and unsupported Hierarchical Condition Category (HCC) assignments – a focus that has netted clawbacks as high as $54.3 million from SCAN Health Plan and $34.4 million from HumanaChoice (administered by Humana, Inc.).

As we discussed in The High-Risk Game of High-Risk Diagnosis Groups, which appeared in the Winter 2023 issue of For the Record, OIG’s focus on improperly used high-risk diagnosis codes isn’t just impacting the payers who are currently the target of investigations; the providers who submitted the claims are being targeted with payer-initiated audits that will inevitably result in repayments to the health plan.

An examination of OIG investigations to date does reveal valuable information that will allow payers and providers alike to take steps to avoid being swept up in OIG’s investigative web. Specifically, all the audits have targeted the same seven high-risk diagnoses: acute stroke, acute heart attack, acute stroke and acute heart attack combination, embolism, vascular claudication, major depressive disorder, and potentially miskeyed diagnosis codes.

Where Trouble Arises

When it comes to HCC codes, there are a couple of common issues that can expose payers and providers to the risk of audits and repayments. Often, HCC codes can’t be validated due to a lack of supporting documentation, such as failure to show hospitalization for stroke in the previous year in the case of an active claim of acute stroke.

In many cases, the problem lies with an unmaintained problem list that displays every problem a patient has ever had while in the care of a particular physician. Coders can’t possibly know which conditions are active and, as a result, can erroneously base coding decisions on an inactive condition that doesn’t meet the HCC criteria.

The use of computer-assisted coding (CAC) is at the heart of a second common problem. Specifically, while CAC can “read” the documentation, it can’t distinguish between active and inactive conditions on the problem list. Thus, the code it recommends may not be supported, requiring the coder to intervene with critical thinking and the application of guidelines to prevent it from making the claim and, ultimately, a failed audit.

In short, effective problem list governance and developing criteria and guidelines to help determine what is a reportable diagnosis are both important for protecting against future repayment demands.

Problem Avoidance

To further protect against errors, we offer the following detailed diagnosis coding tips for the high-risk categories that put providers and payers at the most risk of audits and repayments.

  1. Acute Stroke: With stroke coding, it is vital to carefully review documentation to understand if it is an acute stroke, a sequela or “late effect” from a previous stroke, or a personal history of a stroke with no sequela conditions present. Detailed physician documentation and following ICD-10-CM coding guidelines and conventions are key for correct code assignment.

    Radiology reports can also be utilized to provide greater specificity of the anatomical site of the stroke if the diagnosis is given by the physician. According to AHA Coding Clinic, 1Q2013, Pages 28-29, “If the x-ray report provides additional information regarding the site for a condition that the provider has already diagnosed, it would be appropriate to assign a code to identify the specificity that is documented in the x-ray report.”

  2. Additionally:

    • Sequela of CVA: ICD-10-CM diagnosis code category I69, Sequelae of cerebrovascular disease, indicates conditions in I60-I67 as the cause of sequelae. It specifies the type of stroke that caused the sequela as well as the residual condition. Per ICD-10-CM Coding Guidelines, the “sequelae” is the residual effect after the acute phase of an illness or injury has terminated. For subsequent admissions following the acute stroke, if the residual effect is still present, it is reported as a sequela (late effect).
    • Personal History of Cerebrovascular Accident: If a patient has a history of a previous cerebrovascular accident (CVA) and has no residual conditions from a previous CVA, the correct ICD-10-CM diagnosis code assignment is Z86.73 (personal history of transient ischemic attack (TIA), and cerebral infarction without residual deficits).
  3. Acute Heart Attack: With myocardial coding, we must be careful to review the documentation to understand if it is an acute type 1 or type 2 myocardial infarction (MI) or a personal history of MI. Again, detailed physician documentation of the underlying etiology and site is essential to supporting the diagnosis.

    Additionally, according to FY 2023 ICD-10-CM Guidelines for acute MI, “For encounters occurring while the myocardial infarction is equal to, or less than, four weeks old, including transfers to another acute setting or a post-acute setting, and the myocardial infarction meets the definition for “other diagnoses,” codes from category I21 may continue to be reported. For encounters after the 4-week time frame and the patient is still receiving care related to the myocardial infarction, the appropriate aftercare code should be assigned rather than a code from category I21. For old or healed myocardial infarctions not requiring further care, code I25.2, Old myocardial infarction, may be assigned.”

    Further, ICD-10-CM diagnosis code I21.A1, Myocardial Infarction, type 2, should be assigned when documentation supports that the MI is due to demand ischemia or ischemic imbalance. Note that the ICD-10-CM tabular states for code I21.A1 to “code first” the underlying cause, such as anemia, shock, chronic obstructive pulmonary disease, or paroxysmal tachycardia.

  4. Embolism or Thrombosis: For accurate ICD-10-CM code assignment for embolism and thrombosis, it’s important to know the site of the embolism or thrombosis as well as if it if the condition is acute, chronic, or personal history. Unfortunately, this is an area subject to significant physician queries because documentation is unclear concerning the current acuity or type of thrombosis or embolism.

    A question coders often face is determining what code to use when documentation states the patient has a personal history of thrombosis or embolism and is actively being treated with anticoagulants. Do they use a personal history or chronic condition code?

    Two AHA Coding Clinics give official coding guidance on this common scenario.

    • AHA Coding Clinic 1Q2011, Page 20, addresses the question of when a physician documents a “history of deep vein thrombosis” and the patient is still receiving anticoagulant. According to the Official Guidelines for Coding and Reporting, query the physician for clarification on whether the anticoagulation therapy is being given prophylactically to prevent a reoccurrence or as a treatment for a chronic condition. Per the AHA Coding Clinic, because there is not any specific timeframe for when DVT or any other condition becomes chronic, the “chronic” should be assigned to provider documentation.

    • AHA Coding Clinic 2Q2020, Pages 20-21, gives additional insight into this common scenario based on the example of a patient with a personal history of recurrent DVT of the lower extremity who is on an anticoagulant. It recommends using codes Z86.718, Personal history of other venous thrombosis and embolism, and code Z79.01, Long term (current) use of anticoagulants. The Coding Clinic goes on to state that “Chronic DVT is a thrombus that is one month to several months old and usually involves symptoms, such as chronic swelling, ulceration, cellulitis, or other complication. Recurrent DVT indicates that the condition has occurred more than once. The provider would need to document recurrent or chronic DVT to code it as such.”

    Again, the power is in the physician’s documentation. When in doubt, query the provider for clarification.

  5. Vascular Claudication: This is another area where physician documentation is essential to the specificity of the code assignment, as is understanding the code book conventions, coding guidelines, and Coding Clinic advice.

    • Peripheral vascular disease (PVD), peripheral arterial disease (PAD), spasm of artery, and intermittent claudication are coded to ICD-10-CM code I73.9, Peripheral vascular disease, unspecified. Documentation for peripheral vascular disease should be as specific as possible to describe the type of disease and identify all related manifestations. ICD-10-CM tabular instructions state that I73.9 excludes atherosclerosis of the extremities (I70.2-I70.7).

    • Peripheral atherosclerosis or arteriosclerosis of the lower extremities is coded to subcategory I70.2 with varying levels of progression from intermittent claudication, rest pain, ulceration, and gangrene. When multiple manifestations are present, only one code from I70 is assigned. Note the subterm “with” listed below the subterm for arteriosclerosis of the extremities. Guideline I.A.15. tells us that conditions listed under “with” have an assumed causal relationship. That means that when a person presents with arteriosclerosis and an ulcer, the conditions are linked unless the provider documents another cause for the ulcer. Per ICD-10-CM tabular instructions, if applicable, you would use an additional code to identify the severity of any ulcer (L97).

    • Because ICD-10-CM presumes a causal relationship between “diabetes” with “peripheral angiopathy,” these conditions should be coded as related even in the absence of provider documentation explicitly linking them unless documentation clearly states the conditions are unrelated.

  6. Major Depressive Disorder: Physician documentation for major depressive disorder should include the episode (single or recurrent), the severity (mild, moderate, severe without psychotic features or severe with psychotic features), and the clinical status of the current episode (in partial/full remission). When physician documentation only states depression or depressive disorder and does not give any other details, F32.A, Depression, unspecified, should be assigned.

Internal Audits as a Safety Net

When it comes to OIG and payer audits, conducting regular internal audits can provide an additional layer of protection by revealing what is happening internally that might make organizations vulnerable to investigation.

Reviewing a set of charts with each of the high-risk codes will show if physicians are documenting with sufficient specificity and if coders are capturing information accurately. Targeted education can then be implemented, supported by a computer-assisted CDI tool, to close gaps and reduce the risk of an external audit.

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