The annual impact of seasonal influenza in the US: measuring disease burden and costs.
Level 5 - mechanism / opinion, no new human data
Mathematical simulation and economic modeling using secondary epidemiological and claims data
PubMed 17544181 · doi:10.1016/j.vaccine.2007.03.046
What was done
Constructed a probabilistic model using publicly available epidemiological data and health insurance claims to estimate age- and risk-specific seasonal influenza burden for the 2003 US population. The model projected influenza-attributable outpatient visits, hospital days, premature deaths, and work absenteeism, calculating direct medical expenses and indirect productivity losses (based on lost earnings and statistical life values) in 2003 US dollars.
What was found
Annual influenza epidemics resulted in an average of 610,660 undiscounted life-years lost, 3.1 million hospitalized days, and 31.4 million outpatient visits. Direct medical costs averaged $10.4 billion (95% CI, $4.1 to $22.2 billion) per year. Annual lost earnings from illness and mortality totaled $16.3 billion (95% CI, $8.7 to $31.0 billion). Total economic burden based on statistical life values was estimated at $87.1 billion (95% CI, $47.2 to $149.5 billion), with productivity and mortality losses forming the majority of the cost.
Why it matters
This study provides a comprehensive baseline for the total economic impact of seasonal influenza in the US, demonstrating that indirect societal costs from missed work and premature mortality substantially exceed direct medical expenditures.
Limits
The findings are derived from mathematical modeling and claims databases rather than direct prospective tracking, leaving results sensitive to coding inaccuracies and underlying model assumptions. Confidence intervals are wide (e.g., $47.2 to $149.5 billion for total economic burden), and estimates reflect US cost structures and population parameters from 2003.
Cited by
- supports The annual direct healthcare burden of the flu season in the United States is approximately $10 billion.