Impact of Inactivated Influenza Vaccination on Health-Related Quality of Life Among Japanese Healthcare Workers

Background

Influenza vaccinations are recommended for healthcare workers (HCWs). Quantification of the personal risks of vaccination compared to vaccine benefits can help guide more accurate benefit-risk assessment and cost-effectiveness analysis of inactivated influenza vaccination among HCWs. The study objective was to evaluate the quality-adjusted life day (QALD) loss due to adverse events following immunization (AEFI) among HCWs.

Methods

This study used a questionnaire survey with the EuroQol-5 dimension-5 level (EQ-5D) for HCWs to evaluate the impact of reactogenicity on QALD loss following inactivated seasonal influenza vaccination. Participants were asked to answer a questionnaire survey regarding their health status once daily from the day before vaccination until 7 days after vaccination (a total of 9 times). QALD loss was calculated as the cumulative difference between the mean EQ-5D scores following vaccination (Days 0–7) and the mean EQ-5D score before vaccination (Day −1).

Results

During the study period, 213 participants completed the surveys for 5 days or more, and 122 participants completed the surveys for all days. The mean QALD losses among the participants who completed the surveys for five or more days and those who completed the surveys on all days were 0.040 and 0.054, respectively. The mean QALD losses among those by grade (the maximal grade of any AEFIs) were 0.021 (grade 0), −0.018 (grade 1), 0.089 (grade 2), and 0.299 (grade 3), respectively.

Conclusion

We measured the magnitude of QALD loss in HCWs following inactivated influenza vaccination. These results support a more accurate health technology assessment of seasonal influenza vaccination in this population.