Cost per Hospitalized Case of Influenza

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Cost per HospitalizedCase of Influenza

• Noelle-Angelique Molinari, PhD
• Ismael Ortega-Sanchez, PhD
• Mark Messonnier, PhD
• National Immunization Program
• CDC

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Outline

• Introduction
• Objective
• Data
• Methods
• Results
• Conclusion

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Introduction

• Every year in the US, Influenza causes
• 36,000 deaths
• 200,000 hospitalizations
• Burden of disease estimates are critical to
  influenza vaccine policy formulation

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Objective

• Update disease burden estimates
• Examine distribution of costs across age and risk
  categories
• Identify important determinants of costs

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Data (1)

• Medstat Marketscan 2001 insurance claims database
• 3,737 patients hospitalized with ILI
• Influenza
• Pneumonia
• Chronic respiratory disease
• Patients followed 30 days pre-admission through
  30 days post-discharge

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Data (2)

• Claims included all payments for
• Inpatient services
• Outpatient services
• Pharmaceutical prescriptions

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Methods

• Patients categorized by age and risk of serious
  complications from influenza
• For each patient
• costs summed over all relevant claims
• Identified place of first treatment
• Regression analysis to identify important factors
  affecting cost per case

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Summary Statistics for All 3,737 Patients (1)
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Summary Statistics for All 3,737 Patients (2)
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Summary Statistics for All 3,737 Patients (3)
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A note on Regression Results

• Regressed natural log of total payments on age,
  risk factors, disease severity, etc.
• Elasticity represents percent change in total
  payments due to change in independent variable
• From 0 to 1
• By 10

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Regression Results (1)
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Regression Results (2)
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Interpretation

• So what matters?
• Age
• Gender
• Region
• Urbanicity
• Insurance Plan

• Risk Status
• Place of 1st treatment
• Severity of illness
• Number of services provided

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Implications and Next Steps

• Seeking treatment early may reduce cost of
  hospitalization from influenza
• Next step
• construct variable to indicate time elapsed from
  1st tx to hospitalization

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