Since the expansion of code 488 and the creation of code 488.1, Influenza due to identified novel H1N1 influenza virus on October 1, 2009, there has been some confusion about the use of code 488.1. Code 488.1 was created to provide data capture for the novel H1N1 influenza virus (swine flu virus), which was first identified in April, after the March 2009 ICD-9-CM Coordination and Maintenance Committee meeting. In response to many requests for assistance in coding the H1N1 flu with pneumonia and suspected H1N1 influenza, the following questions and answers have been provided. This information is also posted on the National Center for Health Statistics (NCHS) website: http://www.cdc.gov/nchs/icd/icd9cm_addenda_guidelines.htm
Patients with H1N1 influenza can develop either bacterial or viral pneumonia. When the documentation does not specify whether the pneumonia is bacterial or viral, assign code 488.1, Influenza due to identified novel H1N1 influenza virus, and code 486, Pneumonia, organism unspecified, for H1N1 influenza with pneumonia. If the provider has documented the specific organism or type of pneumonia (e.g., Streptococcus pneumoniae), it is appropriate to assign the more specific code instead of code 486. Do not assign code 487.0, Influenza with pneumonia, since 487.0 is used for regular seasonal flu, not H1N1 influenza. Sequencing of the principal diagnosis will be dependent on the circumstances of admission.
The patient, a four-year-old female, presents to the hospital with cough, sore throat, and fever. Her symptoms had started suddenly a few days ago, and had worsened progressively, including the development of rigors, body aches, nasal congestion, and rhinorrhea. She was admitted to the hospital to rule out H1N1 influenza and was treated with Tamiflu. The patient's symptoms resolved and she was discharged home in good condition. The provider documented "possible H1N1 flu" in the discharge summary. How should this case be coded?
Assign code 487.1, Influenza with other respiratory manifestations, for possible H1N1 influenza. Only confirmed cases of H1N1 are reported. When the final diagnostic statement indicates "possible," "probable" "suspected" or "questionable" H1N1 influenza infection, code 488.1 is not assigned.
This is an exception to the hospital inpatient guideline that directs the coder to assign a code for a diagnosis qualified at the time of discharge as suspected or possible as if it were established. Refer to the Official Guidelines for Coding and Reporting Section 1.C.8.d. previously published in Coding Clinic Fourth Quarter 2009, page 158, for additional information.