, Volume 21, Issue 4, pp 273–283 | Cite as

A Study of Influenza and Influenza-Related Complications among Children in a Large US Health Insurance Plan Database

  • Jeanne Loughlin
  • Nick Poulios
  • Pavel Napalkov
  • Yann Wegmüller
  • Arnold S. Monto
Original Research Article


Background: Influenza places a substantial burden on the affected individual and society. While there are data available on the overall occurrence of influenza in children, less information is available on the differential impact of influenza on healthcare for previously healthy children and those at high risk of developing influenza-related complications.

Objective: To compare the frequency of influenza-related complications in healthy and ‘at-risk’ children, and quantify the associated use of medical resources and costs.

Design: Data were obtained from a large US-based health insurance plan database.

Main outcome measures and results: A total of 23 188 health insurance claims with an influenza diagnosis were identified over the 3-year period 1995–1997 (3 247 834 patient-years). Influenza-related complications were observed in approximately a quarter of the total diagnosed cases, with younger children (0–4 years of age) at substantially greater risk. ‘At-risk’ children were more likely to develop influenza-related complications than otherwise healthy children. The greatest difference in incidence rate in the 0–4 year age group was for asthma (incidence rate ratio 8.7, 95% CI 5.2–14.4), and in the 5–14 year age group for asthma (incidence rate ratio 8.5, 95% CI 5.2–13.7) and acute sinusitis (incidence rate ratio 2.7, 95% CI 1.2–5.4). The average direct medical costs of influenza in children under 15 years with complications were more than 3.5 times higher than those without.

Conclusions: Measures to prevent and treat influenza-related complications are certainly warranted for at-risk children, although the elevated incidence rates for several common complications even among healthy children should prompt consideration of these measures for all children.


Influenza Acute Otitis Medium Oseltamivir Medical Resource Zanamivir 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This study was financially supported by F. Hoffmann-La Roche Ltd. Nick Poulios, Pavel Napalkov and Yann Wegmüller are employees of F. Hoffmann-La Roche Ltd. Dr Monto is a consultant to Hoffmann-La Roche Ltd. The authors gratefully acknowledge the assistance of Clorinda Cali, Lisa Weatherby and the staff of the Epidemiology Division of Ingenix for their contributions to the analysis of the claims data.


  1. 1.
    Campbell DS, Rumley MH. Cost-effectiveness of the influenza vaccine in a healthy, working-age population. J Occup Environ Med 1997; 39: 408–14PubMedCrossRefGoogle Scholar
  2. 2.
    Sullivan KM. Health impact of influenza in the United States. Pharmacoeconomics 1996; 9 Suppl. 3: 26–33CrossRefGoogle Scholar
  3. 3.
    Sullivan KM, Monto AS, Longini IM. Estimates of the US health impact of influenza. Am J Public Health 1993; 155: 1119–26Google Scholar
  4. 4.
    Kavet JA. Perspectives on the significance of pandemic influenza. Am J Epidemiol 1997; 127: 353–64Google Scholar
  5. 5.
    Couch RB. Advances in influenza virus vaccine research. Ann N Y Acad Sci 1993; 685: 803–12PubMedCrossRefGoogle Scholar
  6. 6.
    Barker WH. Excess pneumonia and influenza associated hospitalization during influenza epidemics in the USA, 1970–1978. Am J Public Health 1986; 76: 761–5PubMedCrossRefGoogle Scholar
  7. 7.
    Meltzer MI, Cox NJ, Fukuda K. The economic impact of pandemic influenza in the United States: priorities for intervention. Emerg Infect Dis 1999; 5: 659–71PubMedCrossRefGoogle Scholar
  8. 8.
    Monto AS, Sullivan KM. Acute respiratory illness in the community: frequency of illness and the agents involved. Epidemiol Infect 1993; 110: 145–60PubMedCrossRefGoogle Scholar
  9. 9.
    Centers for Disease Control. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep 1999; 48 (RR-4): 1–28Google Scholar
  10. 10.
    Izurieta HS, Thompson WW, Kramarz P, et al. Influenza and the rate of hospitalization for respiratory disease among infants and young children. N Engl J Med 2000; 342: 232–9PubMedCrossRefGoogle Scholar
  11. 11.
    National Center for Health Statistics. Current estimates from the National Health Interview Survey, 1994. Vital and health statistics. Series 10, no. 193. DHHS publication no. PHS 96-1521. Washington (DC): Government Printing Office, 1995Google Scholar
  12. 12.
    Perrotta DM, Decker M, Glezen WP. Acute respiratory disease hospitalizations as a measure of impact of epidemic influenza. Am J Epidemiol 1985; 122: 468–76PubMedGoogle Scholar
  13. 13.
    Longini Jr IM, Koopman JS, Monto AS, et al. Estimating households and community transmission parameters for influenza. Am J Epidemiol 1982; 115: 736–51PubMedGoogle Scholar
  14. 14.
    Glezen WP, Couch RB. Interpandemic infection in the Houston area, 1974–1976. N Engl J Med 1978; 298: 587–92PubMedCrossRefGoogle Scholar
  15. 15.
    Fox JP, Hall CE, Cooney MK, et al. Influenza virus infections in Seattle families, 1975–1979: I. study design, methods and the occurrence of infections by time and age. Am J Epidemiol 1982; 116: 212–27PubMedGoogle Scholar
  16. 16.
    Health care financing administration common procedure coding system (HCPCS). Salt Lake City (UT): Medicode, 1999Google Scholar
  17. 17.
    Current procedural terminology (CPT). Chicago (IL): American Medical Association, 1999Google Scholar
  18. 18.
    SAS Institute Inc. SAS/STAT User’s Guide, release 6.12th ed. Cary (NC): SAS Institute Inc, 1997Google Scholar
  19. 19.
    Treanor JJ, Hall CB. Influenza and infections of the trachea, bronchi, and bronchioles. In: Reese RE, Betts RF, editors. A practical approach to infectious diseases. 4th ed. New York: Little Brown, 1996: 240–57Google Scholar
  20. 20.
    Connoly AM, Salmon RL, Lervy B, et al. What are the complications of influenza and can they be prevented?: experience from the 1989 epidemic of H3N2 influenza A in general practice. BMJ 1993; 306: 1452–4CrossRefGoogle Scholar
  21. 21.
    Neuzil KM, Reed GW, Mitchel EF, et al. Influenza-associated morbidity and mortality in young and middle-aged women. JAMA 1999; 281: 901–7PubMedCrossRefGoogle Scholar
  22. 22.
    Glezen WP, Greenberg SB, Atmar RL, et al. Impact of respiratory virus infection on persons with chronic underlying conditions. JAMA 2000; 283: 499–505PubMedCrossRefGoogle Scholar
  23. 23.
    Meier CR, Napalkov PN, Wegmuller Y, et al. Population-based study on incidence, risk factors, clinical complications and drug utilisation associated with influenza in the United Kingdom. Eur J Clin Microbiol Infect Dis 2000; 19: 834–42PubMedCrossRefGoogle Scholar
  24. 24.
    Mullooly JP, Barker WH. Impact of type A influenza on children: a retrospective study. Am J Public Health 1982; 72: 1008–16PubMedCrossRefGoogle Scholar
  25. 25.
    Fleming DM. The contribution of influenza to combined acute respiratory infections, hospital admissions, and deaths in winter. Commun Dis Public Health 2000; 3: 32–8PubMedGoogle Scholar
  26. 26.
    McEvoy GK, editor. American hospital formulary service. Bethesda (MD): American Society of Health-System Pharmacists, 2000Google Scholar
  27. 27.
    Neuzil KM, Mellen BG, Wright PF, et al. The effect of influenza on hospitalizations, outpatient visits, and courses of antibiotics in children. N Engl J Med 2000; 342: 225–31PubMedCrossRefGoogle Scholar
  28. 28.
    Knottnerus JA. Influenza in the Netherlands. Pharmacoeconomics 1996; 9 Suppl. 3: 46–9PubMedCrossRefGoogle Scholar
  29. 29.
    Centers for Disease Control. Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep 2002; 51 (RR-3): 1–34Google Scholar

Copyright information

© Adis International Limited 2003

Authors and Affiliations

  • Jeanne Loughlin
    • 1
  • Nick Poulios
    • 2
  • Pavel Napalkov
    • 3
  • Yann Wegmüller
    • 3
  • Arnold S. Monto
    • 4
  1. 1.Ingenix Epidemiology DivisionNewtonUSA
  2. 2.Medical Outcomes Research & EconomicsRoche PharmaceuticalsNutleyUSA
  3. 3.Health Economics and Strategic PricingF. Hoffmann-La Roche Ltd.BaselSwitzerland
  4. 4.School of Public HealthUniversity of MichiganAnn ArborUSA

Personalised recommendations