In most cases, I code the signs and symptoms the patient is experiencing unless the diagnosis influenza is actually written in the chart, advises Mary Morrall, CPC, practice coder with Physician Associates, PC, in Lansing, Mich. But, rarely does the physician actually say it is the flu. Usually, Morrall ends up coding the patients chief complaint(s), such as nausea with vomiting (787.01) and/or chills with fever (780.6).
Unless there are complicating circumstances, the physician rarely orders the viral studies necessary to determine the actual presence of the influenza virus, adds Jeri Leong, CPC, an independent coding consultant based in Honolulu, Hawaii. Most of the time it is a clinical diagnosis based on presenting symptoms, she says. If the physician applies a diagnosis of influenza or flu, the appropriate ICD-9 category is 487.x.
If a definitive diagnosis is not made, Leong also recommends coding the symptoms as the physician documented them.
As you will see below, assigning a specific influenza ICD-9 code requires a significant amount of information about the patients particular illness.
Different Flu Diagnoses
Several diagnosis codes exist within the category of influenza, Leong notes. These are:
- 487.0 influenza with pneumonia,
- 487.1 influenza with other respiratory manifestations, and
- 487.8 influenza with other manifestations.
The last subcategory also includes flu with gastrointestinal (GI) symptoms, she says. However, coders should be sure to differentiate between influenza with GI symptoms (487.8) and intestinal flu (008.8).
Note: Intestinal flu actually indicates a bacterial infection instead of a viral infection with influenza. That is why it would be reported with 008.8 (intestinal infections due to other organisms, not elsewhere classified).
Influenza with pneumonia (487.0) should not be confused with pneumonia due to parainfluenza virus (480.2), Leong says. Payers may question ED visits with a non-specific influenza code (i.e., 487.8, with other manifestations) because it is often difficult to demonstrate the medical necessity or high enough level of acuity in the ED with routine diagnosis such as flu, says Leong.
Providers may wish to send supporting documentation to substantiate the need for ED services for patients with a flu-like illness. These might be modifying factors such as a very young patient, an elderly patient or a patient with chronic conditions affecting treatment.
Coders Can Report Reason for Visit on UB-92
Facility coders for the hospital emergency department will soon be able to assign presenting signs and symptom codes on the hospitals UB-92 claim form to Medicare carriers.
Starting April 1, 2000, the admitting diagnosis field (field number 76 on the form) will have a dual purpose for outpatient visits like those in the emergency department, advises Trudy Solomon, vice president of the South Carolina Health Alliance, formerly the South Carolina Hospital Association, in West Columbia, S.C. Beginning in April, coders can report a diagnosis code for the reason for the visit in that field as well.
This is an important change for facility coders in the ED. There are times when the definitive diagnosis does not meet the medical necessity requirements of the ED visit or some of the tests and procedures performed, Solomon adds.
According to American Hospital Associations (AHA) guidelines, coders are supposed to assign an ICD-9 code for the definitive diagnosis when it is available.
Medicares decision to allow the dual purpose for field 76either the admitting diagnosis or the reason for the visitallows the coders to report the code that most appropriately represents the reason care was provided to a patient, she says.
In addition to reimbursement and correct coding benefits, the new policy should help alleviate managed care disputes over emergency vs. non-emergency visits. I think the main purpose behind the change will be to help with the prudent layperson requirements to appropriately screen and treat patients, she says.
Coding the presenting signs and symptoms will, in some cases, indicate the medical necessity for a diagnostic test or visit, when the final, definitive diagnosis does not, she says. This should make the coders job easier.