Rapid influenza testing for children adds little to clinical decision-making
Article Outline
- Rothberg MB, Fisher D, Kelly B, Rose DN. Management of influenza symptoms in healthy children: Cost-effectiveness of rapid testing and antiviral therapy. Arch Pediatr Adolesc Med 2005;159:1055-62
- References
- Copyright
EDITOR’S NOTE: Journals reviewed for this issue: Archives of Disease in Childhood, Archives of Pediatrics and Adolescent Medicine, British Medical Journal, Journal of the American Medical Association, Journal of Pediatrics, The Lancet, New England Journal of Medicine, Pediatric Infectious Diseases Journal, and Pediatrics; Gurpreet K. Rana, B.Sc., M.L.I.S, Taubman Medical Library, University of Michigan, contributed to the review and selection of this month’s abstracts.
—John G. Frohna, MD, MPH
Rothberg MB, Fisher D, Kelly B, Rose DN. Management of influenza symptoms in healthy children: Cost-effectiveness of rapid testing and antiviral therapy. Arch Pediatr Adolesc Med 2005;159:1055-62
Question Do the benefits of empiric antiviral therapy for children presenting with influenza-like illness justify the costs and adverse effects of therapy, and should treatment be directed by rapid testing?
Design Cost-effectiveness analysis from the societal perspective using a decision model based on published data.
Setting Physician’s office during an influenza epidemic.
Participants Hypothetical children aged 2, 7, and 15 years.
Intervention Rapid testing or clinical diagnosis followed by treatment with amantadine hydrochloride or oseltamivir phosphate compared with no antiviral therapy.
Outcomes Costs and quality-adjusted life expectancy.
Results Empiric therapy with antiviral medication resulted in the greatest quality-adjusted life expectancy in all age groups. Compared with not treating, antiviral therapy improved quality-adjusted life expectancy by 0.003 quality-adjusted life-years by shortening the duration and reducing complications of illness. In young children, it saved up to $121 per child mostly by avoiding parental work loss. For children old enough to stay at home alone on the last day of illness, not treating was the least expensive strategy. Excluding work loss, antiviral therapy improved quality-adjusted life expectancy at a cost of $800 to $1800 per quality-adjusted life-year saved. Compared with amantadine, oseltamivir was not cost-effective when influenza A predominated. The incremental cost-effectiveness of oseltamivir fell below $50,000 per quality-adjusted life-year saved when the proportion of influenza B exceeded 14% for a 2-year-old, 27% for a 7-year-old, or 43% for a 15-year-old. Rapid testing was cost-effective only when the probability of influenza was 60% or less.
Conclusions In this hypothetical cohort of children presenting with influenza symptoms during a local influenza outbreak, treatment with antiviral therapy appeared to offer the best outcome and often saved money. The choice of antiviral drug should be based on the prevalence of influenza B.
Comment This is a well-executed analysis with conclusions that logically follow the data presented. However, the relevance of the study for current medical care is hampered by several factors. First, some of the baseline assumptions seem imperfect, even with the sensitivity analyses performed. For example, in our prospective population-based surveillance studies, viral-proven influenza disease occurred in 25%, not 68%, of children with influenza-like illness,1 and the sensitivity and specificity of the rapid test used in the analysis was 63% and 97%, rather than the assumed 95% and 72%, respectively.2 More importantly, remarkable geographic and year-to-year variability in influenza epidemics3 make it very difficult to generalize from even carefully analyzed cost-effectiveness algorithms. Finally, recent analyses of the 2005-2006 season’s influenza A isolates reveal unexpectedly high rates of amantadine resistance, which completely negates the utility of empiric therapy with that drug.4 To be fair, this development postdates the authors’ work, but it is exactly situations such as these that are not well-accounted for in hypothetical cost-benefit cohorts.
The conclusions of this report must not automatically instead be generalized to the empiric use of oseltamivir. Our current healthcare system does not allocate healthcare reimbursement equitably—thus, even if some of the scenarios imply that society as a whole might benefit from increased empiric oseltamivir use, parents with inferior or inadequate insurance may not be able to afford to purchase this more expensive agent. Empiric oseltamivir regimens also might induce viral resistance5 and decrease supplies of a valuable medication that might be better directed at interruption of possible pandemic (avian or other) influenza.6 Given these uncertainties, the strongest conclusions of this study are that rapid influenza testing adds very little to clinical decision-making, and that influenza-vaccinated children had lower costs and better health outcomes than non-vaccinated children, regardless of treatment strategy chosen. The latter result was curiously downplayed in this report; in my view, it is perhaps the most important one!
References
- Epidemiology of outpatient visits for influenza infections in young children . Pediatr Res . 2004;55(4 part 2):241A
- Bedside diagnosis of influenzavirus infections in hospitalized children . Pediatrics . 2002;110:83–88
- Epidemiology of respiratory infections in young children (insights from the new vaccine surveillance network) . Pediatr Infect Dis J . 2004;S188–S192
- . High levels of adamantane resistance among influenza A (H3N2) viruses and interim guidelines for use of antiviral agents–United States, 2005-06 influenza season . MMWR Morb Mortal Wkly Rep . 2006;55:44–46
- . Recovery of drug-resistant influenza virus from immunocompromised patients (a case series) . J Infect Dis . 2006;193:760–764
- . The threat of an avian influenza pandemic . N Engl J Med . 2005;352:323–325
PII: S0022-3476(06)00260-5
doi:10.1016/j.jpeds.2006.03.041
© 2006 Elsevier Inc. All rights reserved.
