Economic Burden of Influenza Hospitalization in High-Risk Patient Groups in the US

OBJECTIVES:

Costs associated with influenza-related hospitalizations in the US were evaluated to understand the unmet medical need, overall cost burden, and cost differences by patient risk groups.

METHODS:

IQVIA clinical database management (CDM) and longitudinal prescription claims (LRx) datasets covering ~20M influenza-related claims over 5 years (2015-2019) in the US were acquired. Applying artificial intelligence, datasets were analysed using predictive risk modelling and cost of care analysis.

RESULTS:

Annual costs of influenza-related hospitalizations in the US were estimated at ~ $8B. The average length of stay for influenza-related admissions was 4.5 days, with 20% of patients staying longer than a week. Sixteen percent of hospitalized patients were admitted to ICU.

Age was the strongest single risk factor: > 75% of hospitalizations and ICU admissions occurred in adults aged ≥ 45 years. Patients aged ≥ 65 years accounted for ~$4B, or 50% of annual costs (average $27k per admission). Patients aged 45-64 years with a medical history of lower respiratory disease, heart disease, chronic kidney disease, or sepsis and immune orders accounted for ~ $1.3B of annual costs (average $36k per admission). Per admission costs were highest for patients presenting with myocarditis (average $ 315.2K per admission) but accounted for only 0.2% (~ $14M) of total costs.

Antivirals were prescribed (2017-2019) to 43% of patients: 24% received antivirals prior to hospital presentation, and 21% at the hospital (3% both times). Overall, 13.5% of influenza out-patients and 75% of in-patients received antivirals at some point in their patients’ journey.

CONCLUSIONS:

Despite access to seasonal influenza vaccines and 43% antiviral use, total influenza-related hospitalizations costs in the US remain high. Preventing hospitalization by 30-50% among key risk groups, especially adults aged ≥ 65 years, can reduce annual costs by 20-33%. This suggests there is still a need and market for new, more effective antivirals.