Winter 2023

The High-Risk Game of High-Risk Diagnosis Groups
By Leigh Poland, RHIA, CCS
For The Record
Vol. 35 No. 1 P. 22

The Office of Inspector General (OIG) makes no secret about the investigative target it has placed on Medicare Advantage plans and the use of unsupported hierarchical condition category (HCC) assignments. Over the past 18 months, its investigations have netted clawbacks as high as $54.3 million from SCAN Health Plan.

Nor are health plans the only ones at risk when it comes to high-risk codes. While payers may be the ones writing the checks for improper reimbursements, the providers who submitted the claims are being targeted with audits that will inevitably result in repayments to the health plan.

The good news is that an examination of OIG investigations to date reveals that they all highlight the same seven high-risk diagnoses—valuable information that allows payers and providers to prepare a plan of action to avoid being swept up in the OIG’s investigative web in the first place. These are the following:

• acute stroke;
• acute heart attack;
• acute stroke and acute heart attack combination;
• embolism;
• vascular claudication;
• major depressive disorder; and
• potentially miskeyed diagnosis codes.

Further, knowing what the OIG is looking for, and taking its recommendations on avoiding future overpayments, will go a long way toward preventing loss of revenues to repayments and the costs of defending claims.

Investigative Findings
High-risk diagnosis groups are now part of a high-risk game. A review of HumanaChoice (administered by Humana, Inc) found that the plan had received at least $34.4 million in payments for high-risk diagnosis codes in 2016 and 2017.

The OIG blamed the errors on the policies and procedures HumanaChoice had in place to prevent, detect, and correct noncompliance with the CMS program requirements. Those policies, OIG noted, needed improvement.

Even smaller repayment demands can have a significant impact on a health care organization’s bottom line. For example, a recent review of Blue Cross & Blue Shield of Rhode Island found overpayments totaling $4.8 million. Specifically, the OIG found that most of the selected high-risk diagnosis codes were either not supported by the medical records or Blue Cross & Blue Shield of Rhode Island could not obtain the medical records to support the diagnosis codes.

In every instance, the OIG recommended that the health plans identify similar instances of noncompliance, which could result in the need to refund additional overpayments. OIG also recommended that the health plans examine existing compliance procedures to identify areas for improvement to ensure that diagnosis codes that are at high risk for being miscoded are in compliance when submitted to CMS and take the necessary steps to enhance those procedures.

Where Things Go Wrong
Often, HCC codes cannot be validated due to a lack of supporting documentation. For example, the claims history for acute stroke would need to show a previous inpatient stay for stroke in the previous year. If not, the condition is considered inactive.

While it would be easy to place blame on the coder or physician, it’s not a fair assumption. Often, the issue arises from an unmaintained problem list. When problem lists aren’t properly maintained, they will display every problem a patient has ever had while in the care of a particular physician. Coders have no way of knowing which conditions are active and can erroneously base their coding decisions on an inactive condition that doesn’t meet the HCC criteria.

Another common issue arises from the use of computer-assisted coding. While computer-assisted coding can “read” the documentation, it cannot distinguish between active and inactive conditions on the problem list. As a result, the code it recommends may not be supported. Ensuring that an incorrect code doesn’t make it to the claim requires the coder to intervene with critical thinking and the application of guidelines to catch the error before it sets the stage for a failed audit.

Indeed, in addition to effective problem list governance, developing criteria and guidelines to help determine what is a reportable diagnosis is important to protect against future repayment demands.

Tips to Avoid Trouble
To that end, we have developed the following detailed diagnosis coding tips for the high-risk categories that put providers and payers at most risk of audits and repayments.

1. Acute Stroke: With stroke coding, we must be careful to review the 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.

Some coding reminders for acute stroke coding include the following:

• ICD-10-CM diagnosis code category I60–I62, nontraumatic intracranial hemorrhage specifies the location or source of a hemorrhage as well as the laterality.

- I60- Nontraumatic subarachnoid hemorrhage

- I61- Nontraumatic intracerebral hemorrhage

• ICD-10-CM diagnosis code category I63, cerebral infarction, specifies the cause of the ischemic stroke and the specific location and laterality of the occlusion. Examples of ICD-10-CM codes include the following:

- I63.111, Cerebral infarction due to embolism of right vertebral artery;

- I63.521, Cerebral infarction due to unspecified occlusion or stenosis of right anterior cerebral artery; and

- I63.9, Cerebral infarction, unspecified. ICD-10-CM code I63.9 is utilized when physician documentation states acute “stroke” and doesn’t give any additional information regarding the cause or site of the stroke.

Radiology reports can 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.”

Sequela of cerebrovascular accident (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’s reported as a sequela (late effect).

• Example of ICD-10-CM codes for sequela of stroke/CVA include the following:

- I69.111, Memory deficit following nontraumatic intracerebral hemorrhage;

- I69.292, Facial weakness following other nontraumatic intracranial hemorrhage; and

- I69.920, Aphasia following unspecified cerebrovascular disease.

Personal History of CVA: If a patient has a history of a previous 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, and cerebral infarction without residual deficits).

2. 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. The below reminders are where we see common coding error trends during the coding audit process.

• Type I Acute MI: ICD-10-CM diagnosis code category I21, acute myocardial infarction specifies the types and sites of MIs. ICD-10-CM guideline reminders include the following:

- I21.0, I21.2, and code I21.3 are used for type I ST-elevation myocardial infarctions (STEMIs). STEMI means there is a complete obstruction of one or more coronary arteries causing decreased blood flow and necrosis of myocardial muscle cells.

- I21.4, Non–ST-elevation myocardial infarction (NSTEMI) is used for type 1 NSTEMI. With NSTEMI patients, you see a partial obstruction of one or more coronary arteries that causes decreased blood flow and may cause partial thickness necrosis of muscle cells.

- I21.9, Acute myocardial infarction, unspecified, is the default for unspecified acute MI or unspecified type.

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 postacute setting, and the myocardial infarction meets the definition for ‘other diagnoses,’ codes from category I21 may continue to be reported. For encounters after the four-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.”

• Type 2 MI: Type 2 MI is an MI due to demand ischemia or secondary to ischemic imbalance. The mismatch between oxygen decreased supply and increased demand is caused by conditions such as arrhythmias, embolism, anemia, hypotension, and hypertension. 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. Please note that the ICD-10-CM tabular states for code I21.A1 to “code first” the underlying cause, such as anemia, shock, COPD, or paroxysmal tachycardia.

3. Embolism or Thrombosis: For accurate ICD-10-CM code assignment for embolism and thrombosis, we need to know the site of the embolism or thrombosis as well as if the condition is acute, chronic, or personal history. Unfortunately, this is an area where we see significant physician queries because documentation is unclear concerning the current acuity or type of thrombosis or embolism. Sample ICD-10-CM codes include the following:

• I27.82, Chronic pulmonary embolism;

• I74.3, Embolism and thrombosis of arteries of the lower extremities;

• I82.401, Acute embolism of right femoral vein;

• Z86.711, Personal history of pulmonary embolism; and

• Z87.718, Personal history of other venous thrombosis and embolism.

The common question that many coders are faced with 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—a personal history or chronic condition code? Two AHA Coding Clinics give official coding guidance on this common scenario.

AHA Coding Clinic 1Q 2011 page 20 addresses the question of when a physician documents “history of deep vein thrombosis” (DVT) and the patient is still receiving an anticoagulant. According to the Official Guidelines for Coding and Reporting, “personal history codes explain a patient’s past medical condition that no longer exists and is not receiving any treatment, but that has the potential for recurrence, and therefore may require monitoring.” Query the physician for clarification on whether the anticoagulation therapy is being given prophylactically to prevent a reoccurrence or as treatment for a chronic condition. The AHA Coding Clinic notes there is not any specific timeframe for when DVT or any other condition becomes chronic. The assignment of “chronic” should be assigned to provide documentation.

AHA Coding Clinic 2Q 2020 pages 20–21 give additional insight into this common scenario. The example states that the patient has a personal history of recurrent DVT of the lower extremity and is on an anticoagulant. The question posed is should the coding professional assign a personal history code or should they code it as a chronic condition. The response states to use 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.

4. Vascular Claudication: This is another area where physician documentation is essential to the specificity of the code assignment. Understanding the code book conventions, coding guidelines, and Coding Clinic advice is critical for this area of coding. Included below are a few important reminders regarding coding and documentation for vascular claudication.

Peripheral vascular disease, peripheral arterial disease, 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 sub term “with” listed below the sub term 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). Examples include the following:

• I70.363, Atherosclerosis of unspecified type of bypass graft(s) of the extremities with gangrene, bilateral legs; and

• I70.238, Atherosclerosis of native arteries of right leg with ulceration of other part of foot.

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. AHA Coding Clinic 3Q 2018 page 4 provides further clarification for the scenario of when a patient with diabetes has arteriosclerotic peripheral artery disease. The official coding advice states, “assign code E11.51, Type 2 diabetes mellitus with diabetic peripheral angiopathy without gangrene, along with an additional code from subcategory I70.2, Atherosclerosis of native arteries of extremities, to fully capture the patient’s condition.”

5. 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). Sample codes include the following:

• F32.1, Major depressive disorder, single episode, moderate;

• F32.3, Major depressive disorder, single episode, severe with psychotic features; and

• F33.0, Major depressive disorder, recurrent, mild.

When physician documentation only states depression or depressive disorder and does not give any other details, the coder will assign F32.A, Depression, unspecified.

The Power of the Internal Audit
With OIG and health plans making their audit intentions clear, the best defense is a robust offense in the form of internal audits. A properly conducted coder audit will reveal 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—along with a computer-assisted clinical documentation improvement tool—to close gaps and reduce the risk of an external audit.

Guidance, education, problem list governance, and oversight are the best ways to avoid getting caught up in the high-risk game of high-risk diagnosis groups.

— Leigh Poland, RHIA, CCS, (leigh.poland@agshealth.com) is vice president of AGS Health’s Coding Service Line.