Pathology/Lab Coding Alert

Don't give mistaken AIDS diagnosis.

Making errors when reporting human immunodeficiency virus, acquired immunodeficiency syndrome (HIV/AIDS) could have dire consequences - both for the patient's welfare and your reimbursement. So check out these answers to the three quiz questions and make sure you know how to handle these cases.

Answer 1:
The answer to this question depends on the stage of the infection the patient is in.

After a positive HIV lab test, an appropriate diagnosis for a patient with no symptoms is Z21 (Asymptomatic human immunodeficiency virus [HIV] infection status). Coding Z21 means that the patient is HIV positive, but has yet to show any of the HIV-related conditions or opportunistic infections that are associated with AIDS.

"Using Z21 when the patient is asymptomatic is ideal," agrees Donelle Holle, RN, President of Peds Coding Inc., and a healthcare, coding, and reimbursement consultant in Fort Wayne, Indiana. "If a patient presents with an illness such as a cough or a cold, listing this as a secondary diagnosis is a good option to demonstrate the patient has a chronic condition that could contribute to the complexity of the primary diagnosis."

But, as Kent Moore, senior strategist for physician payment at the American Academy of Family Physicians, cautions, "Be careful to label a patient as HIV positive only if the medical record definitively supports that diagnosis."

That means having a definitive positive result for a test such as 86703 (Antibody; HIV-1 and HIV-2, single result) or 87389 (Infectious agent antigen detection by immunoassay technique, (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative, multiple-step method; HIV-1 antigen(s), with HIV-1 and HIV-2 antibodies, single result).

If the patient has a negative test result, you might still indicate an appropriate HIV status. "For instance," Moore advises, "some patients may be exposed to HIV without actually being infected." In which case, you might code Z20.6 (Contact with and (suspected) exposure to human immunodeficiency virus [HIV]).

In some cases, you might need to report uncertain lab test results. For instance, if an HIV test is inconclusive for a baby born to an AIDS patient, you might code R75 (Inconclusive laboratory evidence of human immunodeficiency virus (HIV)), which could help demonstrate medical necessity for a follow-up HIV test in a week or so.

Once the patient demonstrates any of a number of opportunistic infections associated with HIV infection, the patient is considered to have symptomatic HIV, or AIDS, and the appropriate diagnosis code is B20 (Human immunodeficiency virus [HIV] disease). This continues to be the appropriate code for the patient, even if symptoms abate and the patient encounters the healthcare system for an unrelated condition and has no AIDS symptoms at the time.

Answer 2:
The answer to question 2 about sequencing ICD-10 codes depends on the reason for the patient encounter. If the primary reason for the service, such as a skin biopsy, is for a condition that has manifested due to AIDS, then you should code B20 first in the sequence.

For example, if your pathologist examines a skin biopsy (88305, Level IV - Surgical pathology, gross and microscopic examination, ...Skin, other than cyst/tag/debridement/plastic repair...) and diagnoses Kaposi's sarcoma for a patient with confirmed AIDS, you would code the case listing first B20, and second C46.0 (Kaposi's sarcoma of skin).

"The key is to identify the codes for the conditions you intend to report and follow the guidance ICD-10 provides in each case," Moore says. In this case, there is a note accompanying C46- that says, "Code first any human immunodeficiency virus [HIV] disease" and a corresponding note following B20 that says, "Use additional code(s) to identify all manifestations of HIV infection."

"If ICD-10-CM does not specify a sequence among the codes in question, then align the diagnosis codes with the reasons for the visit," Moore says. For instance, for an AIDS patient undergoing a prothrombin time test (85610, Prothrombin time) to manage blood thinner medication, you would code first the unrelated condition (Z79.01, Long term (current) use of anticoagulants), and code second the HIV status (B20).

Answer 3:
The appropriate code for a woman who is pregnant, who is giving birth, or who has given birth, and who has been diagnosed with HIV is O98.7- (Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium).

That's not all: You must also report another HIV code that indicates the patient's HIV status, such as Z21 if the patient is and always has been asymptomatic for HIV, or B20 if she currently has or has had past conditions or symptoms that resulted in a diagnosis of AIDS.

You should report either of these codes second, following O98.7-, according to ICD-10 guidelines. "Chapter 15 [Pregnancy, Childbirth, and the Puerperium] codes have sequencing priority over codes from other chapters." Also, a note under O98.7- directs you to "Use additional code to identify the type of HIV disease," which would be either Z21 or B20.

You would also add the appropriate fifth and sixth digits to O98.7- to specify the trimester or whether the encounter was before or after the patient gave birth. And if the encounter occurred during the pregnancy, you would add another code from Z3A.- (Weeks of gestation) to indicate how many weeks the patient was into the pregnancy.