Abstract
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.
Similar content being viewed by others
References
Campbell DS, Rumley MH. Cost-effectiveness of the influenza vaccine in a healthy, working-age population. J Occup Environ Med 1997; 39: 408–14
Sullivan KM. Health impact of influenza in the United States. Pharmacoeconomics 1996; 9 Suppl. 3: 26–33
Sullivan KM, Monto AS, Longini IM. Estimates of the US health impact of influenza. Am J Public Health 1993; 155: 1119–26
Kavet JA. Perspectives on the significance of pandemic influenza. Am J Epidemiol 1997; 127: 353–64
Couch RB. Advances in influenza virus vaccine research. Ann N Y Acad Sci 1993; 685: 803–12
Barker WH. Excess pneumonia and influenza associated hospitalization during influenza epidemics in the USA, 1970–1978. Am J Public Health 1986; 76: 761–5
Meltzer MI, Cox NJ, Fukuda K. The economic impact of pandemic influenza in the United States: priorities for intervention. Emerg Infect Dis 1999; 5: 659–71
Monto AS, Sullivan KM. Acute respiratory illness in the community: frequency of illness and the agents involved. Epidemiol Infect 1993; 110: 145–60
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): 1–28
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: 232–9
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, 1995
Perrotta DM, Decker M, Glezen WP. Acute respiratory disease hospitalizations as a measure of impact of epidemic influenza. Am J Epidemiol 1985; 122: 468–76
Longini Jr IM, Koopman JS, Monto AS, et al. Estimating households and community transmission parameters for influenza. Am J Epidemiol 1982; 115: 736–51
Glezen WP, Couch RB. Interpandemic infection in the Houston area, 1974–1976. N Engl J Med 1978; 298: 587–92
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: 212–27
Health care financing administration common procedure coding system (HCPCS). Salt Lake City (UT): Medicode, 1999
Current procedural terminology (CPT). Chicago (IL): American Medical Association, 1999
SAS Institute Inc. SAS/STAT User’s Guide, release 6.12th ed. Cary (NC): SAS Institute Inc, 1997
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: 240–57
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: 1452–4
Neuzil KM, Reed GW, Mitchel EF, et al. Influenza-associated morbidity and mortality in young and middle-aged women. JAMA 1999; 281: 901–7
Glezen WP, Greenberg SB, Atmar RL, et al. Impact of respiratory virus infection on persons with chronic underlying conditions. JAMA 2000; 283: 499–505
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: 834–42
Mullooly JP, Barker WH. Impact of type A influenza on children: a retrospective study. Am J Public Health 1982; 72: 1008–16
Fleming DM. The contribution of influenza to combined acute respiratory infections, hospital admissions, and deaths in winter. Commun Dis Public Health 2000; 3: 32–8
McEvoy GK, editor. American hospital formulary service. Bethesda (MD): American Society of Health-System Pharmacists, 2000
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: 225–31
Knottnerus JA. Influenza in the Netherlands. Pharmacoeconomics 1996; 9 Suppl. 3: 46–9
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): 1–34
Acknowledgements
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.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Loughlin, J., Poulios, N., Napalkov, P. et al. A Study of Influenza and Influenza-Related Complications among Children in a Large US Health Insurance Plan Database. Pharmacoeconomics 21, 273–283 (2003). https://doi.org/10.2165/00019053-200321040-00005
Published:
Issue Date:
DOI: https://doi.org/10.2165/00019053-200321040-00005