ICD-10 Influenza Diagnosis Accuracy Questioned by New Study

Medical coders are tasked with the job of translating clinical text into alpha-numeric codes that describe medical events. Medical billers then use those codes to prepare claims before submitting them to insurance companies. It would seem that something like influenza, as common as it is, would be easy enough to correctly code. But how accurate are actual diagnoses?

 

A newly published study shows mixed results based on whether ICD-9 or ICD-10 codes are utilized. The research indicated that providers and billers can be fairly confident that a correct diagnosis was reported when ICD-10 codes were utilized. There was less confidence when using the ICD-9 code set.

 

Variations in influenza coding do not create huge discrepancies in payments, but they can inhibit clinical studies. For example, pediatric influenza has been studied in detail for years. Future studies may be impacted in meaningful ways if medical codes do not accurately capture a patient's medical condition.

 

A team of researchers from Vanderbilt university medical center wanted to determine the accuracy of ICD-10 codes for influenza diagnosis compared to what was already known about ICD-9 diagnosis. They studied data from seven different pediatric medical centers, data collected from early December 2016 through the end of March 2020. Analysis of the data was conducted in 2023.

 

They specifically looked at the medical codes used at discharge compared to actual lab results. What they discovered was rather interesting. The researchers based their conclusions on three possible outcomes:

When all was said and done, the research determined that "influenza ICD-10 discharge diagnoses were highly specific but moderately sensitive in identifying laboratory-confirmed influenza." The researchers went on to explain that in most cases, an ICD-10 diagnosis probably indicates a true positive case.

 

Researchers had to consider plenty of variables before reaching their conclusions. They noted variations in ICD-10 accuracy based on patient age, the amount of time between onset and testing, and even the definition of influenza season in a given locale. Clinical settings also influenced how and when the ICD-10 diagnosis was utilized.

 

Despite such variations, researchers seem fairly confident that ICD-10 code diagnoses are more accurate for influenza than their ICD-9 counterparts. Patients are apparently more likely to be accurately diagnosed when the ICD-10 code set is in play.

 

So, what does all this mean to you as a medical coder or biller? Very little. Research data doesn't change the fact that medical coders translate clinical notes into numerical codes. Currently, HIPAA requires coders to use ICD-10-CM codes. Although the ICD-9-CM codeset can no longer be used in the U.S., it is likely that sometime in the future, ICD-11 will be implemented and ICD-10-CM will be shelved.

 

If you are a medical biller, your only responsibility is to take the codes you are presented with and translate them into claims prior to submission. Whether or not a molecular test confirms an influenza diagnosis doesn't change the treatment received and, therefore, will not impact billing.

 

The importance of the research is more about studying influenza as a disease. Scientists hope to get accurate information from medical codes because it aids in their studies. In that regard, it is important to get the information right. The need for accurate information supports setting aside ICD-9 codes (as was done in 2015) for what appear to be more accurate ICD-10 codes. Of course, all of this could change after the transition to ICD-11.