OBJECTIVES

As influenza vaccines and antiviral drugs for influenza (antivirals) are reported to be effective for preventing severe symptoms when influenza develops, they may reduce medical expenses after influenza infection. We investigated the medical expenses of the influenza patients who received influenza vaccine or antivirals.

METHODS

We used health insurance claims data from 2015 to 2016 in MarketScan Commercial Database, a claims database of American commercial health plan. This database included approximately 30 million insureds. Influenza patients were identified with ICD-10 codes or ICD-9 codes. Among them, the patients who had at least 6 months insurance exposure before being diagnosed as influenza were extracted as analysis target. We calculated the average medical expenses per patient per month (PPPM) from the month including the first date diagnosed as influenza (index date) to 6 months after the index date. PPPM in the following three cases were compared; a) all influenza patients (all patients), b) patients prescribed influenza vaccine in the last 6 months prior to the index date (vaccinated patients), c) patients prescribed antivirals after the index date (patients treated with antivirals). PPPM was demographically adjusted by sex and age class of the patients.

RESULTS

301,454 patients were extracted for analysis. PPPM for the month including the index date was $1,314 for all patients, $1,386 for vaccinated patients, $1,267 for the patients treated with antivirals. PPPM for the next month of diagnosis was $427 for all patients, $512 for vaccinated patients, $418 for the patients treated with antivirals. After 2 months to 6 months after diagnosis, PPPM of vaccinated patients were still higher than those of the other two cases, and there were no significant difference in PPPM between all patients and the patients treated with antivirals.

CONCLUSIONS

Influenza vaccines and antivirals may not reduce the medical expenses after influenza infection.